Chlorophyll is the green pigment that plants and algae use to turn sunlight into food. Its molecule is a flat ring with a magnesium atom in the middle, and plants make two main forms, chlorophyll a and chlorophyll b. The name comes from the Greek words for pale green and leaf.
Richard Willstätter won the 1915 Nobel Prize in Chemistry for his work on it. He pointed out how closely the ring resembles the one in the hemoglobin of red blood cells, which holds iron instead of magnesium.
What is sold as “liquid chlorophyll” is a different molecule from the pigment in a leaf. Natural chlorophyll does not dissolve in water. So a clear green drop or a bottle of chlorophyll water usually relies on chlorophyllin, a semi-synthetic, water-soluble form.
Makers extract chlorophyll from plants such as alfalfa, cut off its long fat tail and swap the magnesium for copper. Most of the human studies below used chlorophyllin, so this page keeps the two apart and says which one each study tested.
Here is the part few people know. Natural chlorophyll mostly does not survive digestion: stomach acid strips out its magnesium. In a lab model, only 5 to 10% of the digested chlorophyll derivatives were taken up by human gut cells.
Chlorophyllin behaves differently. In a trial in China, many blood serum samples from people taking chlorophyllin tablets were visibly green. Pieces of the molecule had been absorbed into the blood.
Health benefits of chlorophyll
None of the studies below reaches moderate or strong evidence. The best-supported finding is from one randomized trial in China, where chance decided who got the tablets. Chlorophyllin tablets, 300 mg a day, lowered a urine marker of DNA damage from aflatoxin, a mold toxin, by 55% over 4 months. That is a biomarker in a high-risk population, not a cancer result.
For body odor, the one trial against a placebo (dummy pill) that we found had no clear effect. Wheat grass tablets did not lower transfusion needs in thalassemia, an inherited blood disorder. We found no trial of a liquid chlorophyll drink for acne, weight loss or blood.
Nearly every human trial used chlorophyllin tablets or a mixed product, not food. Here is what 24 studies found, strongest evidence first, including the trials that found nothing.
Chlorophyllin tablets cut a urine marker of aflatoxin damage by 55%
This randomized, double-blind, placebo-controlled trial was in 180 healthy adults in Qidong, China, where aflatoxin in food raises liver cancer risk. They took 100 mg of chlorophyllin three times a day for 4 months; the marker, aflatoxin-N7-guanine, comes from aflatoxin binding to DNA. Its median level in urine at 3 months was 55% lower than on placebo (P = 0.036), and no adverse events were reported. It tested a biomarker, not cancer, and the tablets held chlorophyllin, not food chlorophyll.
In 39 trials, a Chinese chlorophyll tablet raised hemoglobin in iron-deficiency anemia
This meta-analysis pooled 39 trials with 4,562 cases of iron-deficiency anemia treated with Shengxuening tablets. Hemoglobin was higher (effect size 1.11, range 0.75 to 1.46) than on comparison treatments, and side effects fewer (0.24 times the risk). Ferritin and some other measures were comparable to iron supplements, and the abstract does not rate trial quality. The tablet’s main components are chlorophyll derivatives and sodium iron chlorophyllin, so iron may explain the result as much as chlorophyll.
Chlorophyllin raised low white cell counts in 85%, vitamin C in 26.7%
In this randomized trial, 105 people with leukopenia, a low white blood cell count, took sodium copper chlorophyllin, a comparison drug or vitamin C. The 60 in the chlorophyllin group took 40 mg three times a day for a month. The comparison drug, Leucogen, worked in 83.3%, which was similar. The vitamin C group had only 15 people, the abstract does not say whether the trial was blinded, and no adverse reactions were found.
Chlorophyllin tablets were reported to help body and fecal odors
This short report covered a test group of 62 older nursing-home patients. The authors also saw less constipation and gas and no toxic effects, and they say the tablets sometimes worked as a morale-building placebo. Their bacteria tests did not confirm that chlorophyllin kills germs. The abstract describes no comparison group and gives no odor scores.
Show 20 more studies
In 53 people, wheat grass tablets did not reduce transfusion needs
Fifty-three patients with thalassemia major, median age 16, took wheat grass juice tablets for one year. The red cells they needed per year went from 288.06 to 301.25 g/kg (p = 0.054), a small rise, not a fall. Wheat grass holds chlorophyll among many other substances, so the trial does not test chlorophyll itself. No adverse effects were noted.
Wheat grass juice: transfusions fell 25% or more in 8 of 16
In this pilot study, people with thalassemia drank about 100 mL of wheat grass juice a day. Each patient was compared with his or her own previous year, with no placebo group. In 3 of the 8, transfusion needs fell more than 40%, and no side effects were seen. The larger trial above found no benefit, and wheat grass juice is not a test of chlorophyll alone.
Chlorophyllin did not clearly cut urinary odor more than placebo
This randomized, double-blind crossover trial gave 20 incontinent older patients with urinary catheters 100 mg of chlorophyllin a day for 2 weeks, and placebo. Odor fell about 21% on chlorophyllin and rose about 9% on placebo. 12 patients improved on chlorophyllin against 6 on placebo, but the difference could be chance. The authors say 100 mg a day for two weeks may not work for mild to moderate urinary odor.
Plant membranes: 5.0 kg lost, against 3.5 kg on placebo
In this randomized trial, 38 overweight women aged 40 to 65 took 5 g a day of green-plant membrane powder or placebo for 12 weeks. Total and LDL cholesterol also fell more on the powder, while waist, body fat and leptin fell in both groups with no difference. The leaf membranes carry chlorophyll along with many other substances, so the result cannot be credited to chlorophyll. Everyone was also told to eat three meals a day and to be more active.
A mixed diet with chlorophyllin nearly halved DNA damage in rectal cells
This controlled feeding study had 16 healthy volunteers on a high-temperature meat diet, such as fried meat. Eight of them compared that diet alone with the same diet plus three “inhibitors”: cruciferous vegetables, yogurt and chlorophyllin tablets, in a crossover design. Because the three were given together, the result cannot be credited to chlorophyllin, and the abstract gives no chlorophyllin dose.
Copper chlorophyllin lowered free trimethylamine in urine in seven patients
Trimethylaminuria is a metabolic disorder in which the body cannot convert trimethylamine (TMA) to its odorless form, TMAO. The seven Japanese patients, who converted 70 to 90% against at least 95% in healthy controls, took 180 mg a day for 3 weeks. Activated charcoal (1.5 g a day for 10 days) also worked, and the effect of chlorophyllin lasted longer, for several weeks. The study is small and describes no placebo group.
Chlorophyllin skin gel improved acne and large pores in 10 people
In this single-center pilot study, 10 people with mild to moderate acne used a liposomal gel with 0.1% sodium copper chlorophyllin. They applied it twice a day for 3 weeks, and all clinical measures improved over baseline. The gel was well tolerated, but with no comparison group, the change cannot be tied to the gel. It was applied to the skin, not drunk.
Chlorophyll or chlorophyllin cut aflatoxin absorption in at least one volunteer
In this unblinded crossover study, four volunteers took 30 ng of radiolabeled (traceable) aflatoxin B1 in a capsule to measure how it is absorbed. Three of them repeated this three times with 150 mg of purified chlorophyll or of chlorophyllin in the capsule. Each lowered the peak blood level and the total exposure in one or more subjects. The authors call the results initial.
Chlorophyllin was well tolerated up to 3000 mg in healthy men
This phase I trial, the first in people, tested sodium copper chlorophyllin in healthy male volunteers, with blood levels above 5 µM. The same paper reports lab and hamster work on the coronavirus that causes COVID-19, which does not show a benefit in people. The authors hold a patent related to the findings, and the work was funded by India’s Department of Atomic Energy.
Papain-urea ointment cleared dead pressure-ulcer tissue faster than collagenase, on limited evidence
This systematic review covered studies from 1960 to February 2008 on enzymatic debridement (clearing dead tissue with enzymes) of pressure ulcers, leg ulcers and burns. For pressure ulcers, papain-urea ointment, with or without chlorophyllin, cleared dead tissue faster than collagenase, but healing progress was equivocal. Chlorophyllin was never tested on its own, so its part in the ointment cannot be separated from papain and urea.
Of 16 papain-urea wound studies, only 4 had a control treatment
This literature review of enzymatic wound-cleaning agents, including papain-urea products with or without chlorophyllin, found 16 of 44 relevant citations met its criteria. Thirteen had limited external validity because of small samples. Only four reported a statistically significant difference. The author calls for better-designed studies.
Dutch men with more heme iron than chlorophyll had more colon cancer
The Netherlands Cohort Study followed 120,852 people aged 55 to 69 for 9.3 years, with 1,535 colorectal cancers. Chlorophyll was estimated from vegetable questions using values from the literature, not measured. In men, colon cancer rate ratios rose from 1.00 to 1.43 across fifths of the heme-to-chlorophyll ratio (P for trend = 0.01). There was no such trend in women, and the authors say further research is needed.
In trout, chlorophyllin sharply cut an aflatoxin look-alike in liver and bile
In the test tube, chlorophyllin formed a complex with aflatoxin B2 (dissociation constant 1.92 µM), an aflatoxin look-alike. Rainbow trout, not people, got it by mouth with enough chlorophyllin to bind more than 99%. After 3 hours, aflatoxin B2 equivalents in liver and bile were 80 to 90% lower. Aflatoxin B2 cannot form the toxic epoxide, so the study tracks uptake only.
In trout, dietary chlorophyll lowered liver and stomach tumors from a carcinogen
Duplicate groups of 140 trout ate dibenzo[a,l]pyrene (224 ppm) for 4 weeks, with or without 1000 to 6000 ppm chlorophyll. Liver tumors fell from 51% to 21, 28 and 26% at 2000, 4000 and 6000 ppm. Stomach tumors fell from 56% to 29, 23 and 19%. Chlorophyllin at 2000 ppm protected about as well, and both bind the carcinogen in the test tube, which may explain it.
In rats, natural chlorophyll blocked heme’s colon damage; chlorophyllin did not
Rats ate heme, a stand-in for red meat, for 14 days (8 per group). Some also got 1.2 mmol/kg of chlorophyll, chlorophyllin or copper chlorophyllin. Heme raised the toxicity of fecal water more than 50-fold and nearly doubled cell growth in the colon lining. Chlorophyll prevented these effects and the two chlorophyllins did not, so results for one form should not be carried over to the other.
In mice, no diet lowered lymphoma deaths; tube-fed chlorophyllin did
Pregnant mice ate 2000 ppm chlorophyllin, 2000 ppm chlorophyll or 10% freeze-dried spinach, and their offspring were exposed to dibenzo[a,l]pyrene. The diets did not lower lymphoma deaths and had little effect on lung tumors. Chlorophyllin at 380 mg/kg given by tube with the carcinogen cut lymphoma deaths and lowered lung tumor numbers by about 50%. The authors support carcinogen binding as the mechanism.
In gut cells, only 100 µM chlorophyllin reduced aflatoxin B1 transport
Caco-2 cell layers mimic the lining of the human gut; 1 and 10 µM chlorophyllin did not reduce aflatoxin B1 transport. Chlorophyllin did reduce transport of dibenzo[a,l]pyrene at all doses tested, but not of PhIP, a cooked-meat carcinogen that binds it less tightly. The authors read this as support for binding in the gut as one way chlorophyllin may work.
In test tubes, chlorophyllin blocked over 90% of a hydroxyl radical signal
In these electron spin resonance experiments, the radical signal was made by radiation. Chlorophyllin also inhibited a singlet-oxygen signal and the oxidation of phenol red by hydrogen peroxide, but results with the Fenton reaction were different. These are test-tube results at 1 millimolar and say little about what happens in the body.
In pig wounds, papain ointments increased skin cells, blood vessels and collagen
This infected pig wound model compared four ointments with moist wound care. The abstract reports more keratinocytes (skin cells), more new blood vessels and more mature collagen in the papain and papain-urea-copper chlorophyllin groups. It does not report these for copper chlorophyllin alone. The first author is listed at DFB Pharmaceuticals, not at a university.
Without the BCRP pump, mice on pheophorbide a got severe sun lesions
Pheophorbide a is a chlorophyll breakdown product found in plant foods and food supplements. The BCRP protein pumps it out of the gut, and mice lacking it developed severe, sometimes lethal, sun-induced skin lesions. The authors say people with low BCRP activity may be at higher risk of diet-dependent sun sensitivity. This is a mouse study, and the human cases are in the safety section.
Foods high in chlorophyll
Chlorophyll is in every green leaf, so leafy greens, herbs and young shoots are the main food sources. NutriScrolls has no USDA ranking for chlorophyll, because no food in our database has a measured value. So the table below uses published measurements.
Papers report different units and different weight bases (fresh or dry), and values vary with variety, growing conditions, age and storage. Where we added chlorophyll a and b or converted units ourselves, the table says so.
In the papers we could read, fresh-cut spinach held about 115 mg per 100 g and fresh kale about 121 mg. Collard greens held about 43 mg, and alfalfa and fennel microgreens about 79 and 71 mg per 100 g. The dry matter of wheat and barley microgreens reached 617 mg per 100 g. Heat and storage lower the amount: sous vide cooking left about 83% of the chlorophyll in collards.
The average European adult eats about 207 mg of green chlorophylls a day, with olive oil, kale and spinach the leading sources. National averages for adults run from 44.40 mg a day in Denmark to 434.99 mg in the Netherlands. In five Mediterranean leafy vegetables, garden rocket (arugula) had the most.
We found no measured values we could read, with a clear weight basis, for parsley, wheat grass juice, chlorella, spirulina or “liquid chlorophyll” drops.
| Food | Amount per 100 g, unless stated | Source |
|---|---|---|
| Spinach, fresh-cut, unwashed (market, Türkiye) | Chlorophyll a 682 and b 469 mg/kg as published, so about 115 mg per 100 g by our addition | 1 |
| Kale, fresh leaves | About 121 mg of chlorophylls; about 646 mg in air-dried leaves | 2 |
| Collard greens, fresh-cut | 428 µg/g fresh weight (chlorophyll a 276, b 152), about 43 mg per 100 g | 3 |
| Collard greens, after sous vide cooking | 357 µg/g fresh weight, about 36 mg per 100 g | 3 |
| Collard greens, freeze-dried powder | 3,461 µg/g, about 346 mg per 100 g | 3 |
| Alfalfa microgreens | 0.785 mg/g fresh weight (chlorophyll a 0.536, b 0.248), about 79 mg per 100 g | 4 |
| Fennel microgreens | 0.713 mg/g fresh weight, about 71 mg per 100 g | 4 |
| Wheat and barley microgreens, day 16 | Up to 616.63 mg per 100 g of dry matter (dry basis, not comparable with fresh values) | 5 |
Sources
- Demircan B, Velioglu YS, Giuffrè AM, et al. Effects of washing with boric acid solutions on residual boric acid content, microbiological load, and quality of fresh-cut spinach. Heliyon. 2024. The paper gives mg/kg and does not state the weight basis; the leaves were fresh.
- Kowalska H, Salamon A, Wolska-Wilk J, et al. The effect of hybrid convective-infrared-ultrasonic drying on selected properties of kale and nutritional value of kale bars. Molecules. 2026. The kale values are quoted there from Korus A, J Food Process Preserv, 2013.
- Canazza E, Tessari P, Mayr Marangon C, Lante A. Nutritional profile and chlorophyll intake of collard green as a convenience food. Nutrients. 2024. The 346 mg per 100 g and 36 mg per 100 g figures are our conversion from µg/g.
- Fabek Uher S, Radman S, Opačić N, et al. Alfalfa, cabbage, beet and fennel microgreens in floating hydroponics: perspective nutritious food?. Plants (Basel). 2023.
- Niroula A, Khatri S, Timilsina R, et al. Profile of chlorophylls and carotenoids of wheat and barley microgreens. J Food Sci Technol. 2019.
- Roca M, Pérez-Gálvez A. Application of EFSA EU menu database and R computing language to calculate the green chlorophyll intake in the European population. Food Chem. 2024. The national range is quoted from Canazza et al. (source 3).
- Znidarčič D, Ban D, Sircelj H. Carotenoid and chlorophyll composition of commonly consumed leafy vegetables in Mediterranean countries. Food Chem. 2011.
How chlorophyll works
Most of what we know about how chlorophyll and chlorophyllin work comes from test tubes, cells and animals. Researchers keep coming back to three ideas. Natural chlorophyll breaks down in the gut while chlorophyllin partly survives, and chlorophyllin sticks to some carcinogens and may keep them from being absorbed. It also mops up reactive oxygen in test tubes.
Here is each one, and what has been seen in people.
Natural chlorophyll falls apart on the way down
In a lab model of digestion, stomach acid turned the chlorophylls in spinach puree into pheophytins, which have lost their magnesium. A 2020 review says natural chlorophylls and their breakdown products have little to no bioavailability (absorption) themselves. EFSA, the European food safety agency, found that chlorophylls are poorly absorbed by people and are not turned into chlorophyllins.
Natural chlorophyll is a ring around magnesium with a long fat tail. Chlorophyllin is made in a factory, and a common commercial form swaps the magnesium for copper. Commercial chlorophyllin is a mixture of related molecules, and a sodium chlorophyllin that keeps its magnesium (E 140(ii)) also exists.
Uptake is low even after digestion. Human gut cells in a dish took up only 5 to 10% of the digested chlorophyll derivatives. For the carotenoids lutein and beta-carotene, it was 20 to 40%.
Drawn to scale. The solid part of each bar is the low end of the published range and the pale part is the rest of it. The pigments came from a lab model of digestion and were applied to human gut cells in a dish, not to people.
Chlorophyllin is different. Many serum samples from the Qidong chlorophyllin trial, the same trial as the first study card above, were green. Two copper chlorin molecules from the tablet had been absorbed into the blood.
In 2015 EFSA noted that, unlike natural chlorophylls, some components of copper chlorophyllins can be absorbed and spread through the body. It said the data were too thin to assess their safety.
It sticks to some carcinogens in the gut
Chlorophyll and chlorophyllin can form loose, non-covalent complexes with flat carcinogens such as aflatoxin and dibenzo[a,l]pyrene. The idea is that a bound carcinogen is absorbed less.
In trout this fits. With enough chlorophyllin to bind more than 99% of an aflatoxin look-alike, liver and bile levels were 80 to 90% lower. Chlorophyll in the feed also lowered tumor rates from a carcinogen. In human gut cells, only 100 µM chlorophyllin reduced aflatoxin B1 transport.
Drawn to scale, from the percentages in the abstract. Chlorophyllin at 2,000 ppm gave similar protection and is not charted. These are trout fed a carcinogen, not people.
Not every test agrees. In rats, natural chlorophyll blocked the colon damage that heme causes, but two chlorophyllins did not. In pregnant mice, chlorophyllin in the diet did not lower lymphoma deaths from a carcinogen, although chlorophyllin given by tube together with the carcinogen did. Results for one form, one route or one carcinogen cannot be assumed for another.
It mops up reactive oxygen in test tubes
In electron spin resonance experiments, 1 mM chlorophyllin blocked more than 90% of a hydroxyl radical signal. It also inhibited a singlet-oxygen signal and hydrogen peroxide oxidation, though the Fenton reaction gave different results.
A 2015 review lists effects of chlorophyllin on cell-signaling pathways such as NF-κB and Wnt/β-catenin in experimental studies. We found no human trial showing that any of this changes a health outcome.
What has been seen in people
The binding idea has the most human support, and it is still thin. One trial of 180 adults found a lower urine marker of aflatoxin damage. A three-volunteer study found lower aflatoxin absorption in at least one person, but neither measured cancer.
The antioxidant idea has no human test among the cards above. For odor, the placebo-controlled trial found no clear effect. And the rat study is a reminder that the natural chlorophyll in food and the chlorophyllin in tablets should not be assumed to act alike.
Sources
- Ferruzzi MG, Failla ML, Schwartz SJ. Assessment of degradation and intestinal cell uptake of carotenoids and chlorophyll derivatives from spinach puree using an in vitro digestion and Caco-2 human cell model. J Agric Food Chem. 2001.
- Viera I, Pérez-Gálvez A, Roca M. Green natural colorants. Molecules. 2019.
- Hayes M, Ferruzzi MG. Update on the bioavailability and chemopreventative mechanisms of dietary chlorophyll derivatives. Nutr Res. 2020.
- EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on the re-evaluation of chlorophylls (E 140(i)) as food additives. EFSA J. 2015;13(5):4089.
- EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on re-evaluation of copper complexes of chlorophylls (E 141(i)) and chlorophyllins (E 141(ii)) as food additives. EFSA J. 2015;13(6):4151.
- Egner PA, Stansbury KH, Snyder EP, et al. Identification and characterization of chlorin e(4) ethyl ester in sera of individuals participating in the chlorophyllin chemoprevention trial. Chem Res Toxicol. 2000.
- Egner PA, Wang JB, Zhu YR, et al. Chlorophyllin intervention reduces aflatoxin-DNA adducts in individuals at high risk for liver cancer. Proc Natl Acad Sci U S A. 2001.
- Simonich MT, McQuistan T, Jubert C, et al. Low-dose dietary chlorophyll inhibits multi-organ carcinogenesis in the rainbow trout. Food Chem Toxicol. 2008.
- Hayashi T, Schimerlik M, Bailey G. Mechanisms of chlorophyllin anticarcinogenesis: dose-responsive inhibition of aflatoxin uptake and biodistribution following oral co-administration in rainbow trout. Toxicol Appl Pharmacol. 1999.
- Mata JE, Yu Z, Gray JE, et al. Effects of chlorophyllin on transport of dibenzo(a,l)pyrene, 2-amino-1-methyl-6-phenylimidazo-[4,5-b]pyridine, and aflatoxin B(1) across Caco-2 cell monolayers. Toxicology. 2004.
- de Vogel J, Jonker-Termont DS, Katan MB, van der Meer R. Natural chlorophyll but not chlorophyllin prevents heme-induced cytotoxic and hyperproliferative effects in rat colon. J Nutr. 2005.
- Castro DJ, Löhr CV, Fischer KA, et al. Identifying efficacious approaches to chemoprevention with chlorophyllin, purified chlorophylls and freeze-dried spinach in a mouse model of transplacental carcinogenesis. Carcinogenesis. 2009.
- Kumar SS, Devasagayam TP, Bhushan B, Verma NC. Scavenging of reactive oxygen species by chlorophyllin: an ESR study. Free Radic Res. 2001.
- Nagini S, Palitti F, Natarajan AT. Chemopreventive potential of chlorophyllin: a review of the mechanisms of action and molecular targets. Nutr Cancer. 2015.
- Jubert C, Mata J, Bench G, et al. Effects of chlorophyll and chlorophyllin on low-dose aflatoxin B(1) pharmacokinetics in human volunteers. Cancer Prev Res (Phila). 2009.
- Chlorophyll. Wikipedia. Used for the fact that chlorophyll does not dissolve in water.
Is chlorophyll safe? Supplements, dose and interactions
Chlorophyll from vegetables is a normal part of the diet. EFSA reviewed the food color E 140(i), natural chlorophylls, in 2015. It set no numeric acceptable daily intake (ADI) because the toxicity data were limited. It concluded that at the reported use levels the additive is not a safety concern, because it adds less than the regular diet.
The copper complexes of chlorophyllins (E 141(ii)) are the form used in many of the trials above. In 2015 EFSA concluded that their safety could not be assessed because reliable data were lacking, and that the existing ADI should be withdrawn.
In the US, 21 CFR 73.125 lists sodium copper chlorophyllin as a color for citrus-based dry beverage mixes, up to 0.2 percent of the mix. 21 CFR 73.1125 lists potassium sodium copper chlorophyllin for coloring dentifrices (toothpastes) that are drugs, up to 0.1 percent. We found no official upper intake level for chlorophyll or chlorophyllin from supplements.
- Trial doses and side effects. Trials used 100 mg three times a day for 4 months with no adverse events, and 100 mg a day for 2 weeks. Others used 40 mg three times a day for a month with no adverse reactions, and 180 mg a day for 3 weeks. A phase I trial found 3000 mg well tolerated, though its authors hold a patent. MedlinePlus calls chlorophyll nonpoisonous, says most people have no symptoms, and lists rare diarrhea, loose stools and stomach cramps. It also says the tongue may look yellow or black and urine or stool may look green.
- Copper, pregnancy and interactions. FDA’s specification for sodium copper chlorophyllin sets total copper at 4 to 6 percent, and the molecule is partly absorbed, as the green serum showed. We found no study of how much copper the body takes up from tablets, so people told to limit copper should ask a clinician first. We found no safety trials in pregnancy or breastfeeding. Because chlorophyllin is thought to work by binding flat molecules in the gut, it could in theory bind some medicines taken at the same time. We found no study that tested this.
- Sun sensitivity from old or concentrated sources. Pheophorbide a, a chlorophyll breakdown product, makes skin react to light. In a 1984 report, five patients developed swelling and purple-red patches on sun-exposed skin after eating chlorella tablets. The culprit in the tablets was pheophorbide a and its ester. Japan’s health ministry records 7 chlorella cases. It says the midgut gland of abalone (a sea snail) is toxic from February to May. In a 1947 outbreak, 16 people were affected and recovered in about 20 days. We found no such case report for chlorophyllin tablets.
- Wound ointments. Ointments that combine papain, urea and chlorophyllin copper complex were covered when FDA ordered unapproved topical papain products off the market in 2008. It cited serious adverse events, including hypersensitivity and anaphylactic (severe allergic) reactions. Makers had to stop manufacturing by November 24, 2008 and shipping by January 21, 2009. Chlorophyllin was named only as an ingredient, and the action did not single it out.
How to get more chlorophyll
- Best food. Fresh leafy greens such as spinach and kale held about 115 to 121 mg per 100 g in the papers above. Alfalfa microgreens held about 79 mg.
- Keep it green and lightly processed. Cooking turns chlorophyll into pheophytin, and sous vide cooking left about 83% of the chlorophyll in collards. In a lab model of digestion, the share of spinach pigments (carotenoids and chlorophylls together) released for absorption depended on processing. It was 25.8 to 29.3% for juiced, 19.5 to 27.9% for fresh, 14.9 to 20.5% for blanched and 10.4 to 13.0% for sterilized spinach.
- Food versus supplement. We found no trial of a liquid chlorophyll drink. The best human numbers come from chlorophyllin tablets, a different molecule from leaf chlorophyll, so they cannot be carried over to food. If you choose a product, check whether it is chlorophyllin, which copper or sodium form, and the dose per serving. Ask a clinician if you take medicines.
Sources
- EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on the re-evaluation of chlorophylls (E 140(i)) as food additives. EFSA J. 2015;13(5):4089.
- EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on re-evaluation of copper complexes of chlorophylls (E 141(i)) and chlorophyllins (E 141(ii)) as food additives. EFSA J. 2015;13(6):4151.
- 21 CFR 73.125: Sodium copper chlorophyllin. Code of Federal Regulations, US Food and Drug Administration.
- 21 CFR 73.1125: Potassium sodium copper chlorophyllin (chlorophyllin-copper complex). Code of Federal Regulations, US Food and Drug Administration.
- Chlorophyll poisoning. MedlinePlus, US National Library of Medicine. Reviewed October 14, 2025.
- Egner PA, Wang JB, Zhu YR, et al. Chlorophyllin intervention reduces aflatoxin-DNA adducts in individuals at high risk for liver cancer. Proc Natl Acad Sci U S A. 2001.
- Nahata MC, Slencsak CA, Kamp J. Effect of chlorophyllin on urinary odor in incontinent geriatric patients. Drug Intell Clin Pharm. 1983.
- Gao F, Hu XF. Analysis of the therapeutic effect of sodium copper chlorophyllin tablet in treating 60 cases of leukopenia. Chin J Integr Med. 2005.
- Yamazaki H, Fujieda M, Togashi M, et al. Effects of the dietary supplements, activated charcoal and copper chlorophyllin, on urinary excretion of trimethylamine in Japanese trimethylaminuria patients. Life Sci. 2004.
- Patwardhan RS, Rizvi ZA, Gota V, et al. First-in-human clinical trial of high-dose sodium copper chlorophyllin: pharmacology and efficacy as a dual immunomodulatory/antiviral agent. Phytomedicine. 2026.
- Egner PA, Stansbury KH, Snyder EP, et al. Identification and characterization of chlorin e(4) ethyl ester in sera of individuals participating in the chlorophyllin chemoprevention trial. Chem Res Toxicol. 2000.
- Jitsukawa K, Suizu R, Hidano A. Chlorella photosensitization. New phytophotodermatosis. Int J Dermatol. 1984.
- Natural toxins risk profile: marine snails, pheophorbide a (photosensitization). Ministry of Health, Labour and Welfare, Japan. In Japanese.
- Jonker JW, Buitelaar M, Wagenaar E, et al. The breast cancer resistance protein protects against a major chlorophyll-derived dietary phototoxin and protoporphyria. Proc Natl Acad Sci U S A. 2002.
- Questions and answers about FDA’s enforcement action regarding unapproved topical drug products. US Food and Drug Administration.
- Roca M, Pérez-Gálvez A. Application of EFSA EU menu database and R computing language to calculate the green chlorophyll intake in the European population. Food Chem. 2024.
- Canazza E, Tessari P, Mayr Marangon C, Lante A. Nutritional profile and chlorophyll intake of collard green as a convenience food. Nutrients. 2024.
- Hayes M, Corbin S, Nunn C, et al. Influence of simulated food and oral processing on carotenoid and chlorophyll in vitro bioaccessibility among six spinach genotypes. Food Funct. 2021.
- Viera I, Pérez-Gálvez A, Roca M. Green natural colorants. Molecules. 2019. Used for the EU food color rules (Regulation (EC) No 1333/2008) that list E 140 and E 141.
History of chlorophyll
Chlorophyll was named in Paris. In 1817 the pharmacists Pierre-Joseph Pelletier and Joseph Bienaimé Caventou isolated the green pigment from plants and used the word in French. A 2024 paper gives English translations of their 1817 paper and 1818 note.
Richard Willstätter then spent 1906 to 1914 on its chemistry. He showed that the chlorophyll of different plant species is the same, a mixture of two types that he made in pure form. He found that magnesium is an essential part. He also pointed out its relationship with hemoglobin, and he won the 1915 Nobel Prize in Chemistry “for his researches on plant pigments, especially chlorophyll.”
Hans Fischer mapped the heme group of hemoglobin and made it artificially in 1929. He studied chlorophyll too, and won the 1930 prize for researches into the constitution of haemin and chlorophyll.
Robert Woodward synthesized many natural substances in the 1950s and 1960s, including chlorophyll. He won the 1965 prize for his achievements in organic synthesis. His total synthesis of chlorophyll was published by 1960.
Chlorophyll reached the drugstore in the 1950s. Papers on chlorophyllin as a deodorant appeared in 1951, 1953 and 1954. Between 1950 and 1953, companies sold chlorophyll in toothpaste, soap and other goods as an odor blocker. The claims did not hold up, and makers dropped them.
The Qidong trial that tested chlorophyllin against aflatoxin ran in 1997. In the 2020s, social media brought chlorophyll water back with medical claims that lack support.
Sources
- Govindjee G, Stirbet A, Lindsey JS, Scheer H. On the Pelletier and Caventou (1817, 1818) papers on chlorophyll and beyond. Photosynth Res. 2024.
- Richard Willstätter: facts. NobelPrize.org. Prize motivation from the 1915 prize summary.
- Hans Fischer: facts. NobelPrize.org. Prize motivation from the 1930 prize summary.
- Robert B. Woodward: facts. NobelPrize.org.
- Chlorophyll. Wikipedia. Used for the 1960 Woodward synthesis and the 1950 to 1953 marketing.
- Chlorophyllin. Wikipedia. Used for the 2020s social media claims.
- Masson. Considerations on the use of chlorophyllin in otorhinolaryngology; study on its deodorizing action in halitosis. Rev Laryngol Otol Rhinol (Bord). 1951. Title read in PubMed.
- Voigtländer HW. Chlorophyll as deodorant. Arzneimittelforschung. 1953. Title read in PubMed.
- Lu FC. Some observations on the deodorant actions of chlorophyllin. Can Serv Med J. 1954. Title read in PubMed.
- Egner PA, Stansbury KH, Snyder EP, et al. Identification and characterization of chlorin e(4) ethyl ester in sera of individuals participating in the chlorophyllin chemoprevention trial. Chem Res Toxicol. 2000. Gives the 1997 date of the Qidong trial.
Frequently asked questions about chlorophyll
What does chlorophyll do for the body?
No finding reaches moderate or strong evidence. The best-supported result is from one trial in China. There, chlorophyllin tablets, 100 mg three times a day for 4 months, cut a urine marker of aflatoxin damage by 55%. Small trials of odor, anemia, white blood cell counts and acne are mixed or had no control group.
Whether eating leafy greens does the same through chlorophyll has not been tested.
What is the difference between chlorophyll and chlorophyllin?
Chlorophyll is the natural green pigment, with a magnesium center and a long fat tail, and it does not dissolve in water. Chlorophyllin is made in a factory. The tail is cut off, the magnesium is often replaced with copper, and the product is usually a sodium salt that dissolves in water. In rats, natural chlorophyll blocked heme’s colon damage while chlorophyllins did not, so results for one form do not carry over to the other.
Does liquid chlorophyll work for acne or weight loss?
We found no trial of a liquid chlorophyll drink for either. A 10-person pilot of a 0.1% chlorophyllin gel on the skin improved acne measures but had no comparison group. The weight trial used 5 g a day of green-plant membranes, not chlorophyll, and women lost 5.0 kg against 3.5 kg on placebo.
Which foods are highest in chlorophyll?
Leafy greens, young shoots and herbs. In published measurements, fresh-cut spinach held about 115 mg per 100 g and fresh kale about 121 mg. Alfalfa microgreens held about 79 mg and collard greens about 43 mg.
Dried products are far higher by weight, for example 3,461 µg/g in freeze-dried collards. Olive oil, kale and spinach are the leading sources in the average European diet.
Does chlorophyll get rid of body odor?
The evidence is weak. In a crossover trial of 20 incontinent older patients, 100 mg a day for 2 weeks did not clearly beat placebo for urinary odor. A 1980 report in 62 nursing-home patients called chlorophyllin helpful but described only a test group. In 7 people with trimethylaminuria, copper chlorophyllin at 180 mg a day lowered urinary trimethylamine.
How much chlorophyll should you take a day?
No dose is proven best, and we found no official upper intake level for supplements. Trials used 100 mg three times a day, 40 mg three times a day and 180 mg a day of chlorophyllin. A phase I trial found 3000 mg well tolerated in healthy men.
EFSA said in 2015 that the safety of copper chlorophyllins could not be assessed. Ask a clinician before taking more than a label suggests.
Does chlorophyll have side effects?
Green urine or stool, and sometimes a yellow or black tongue, are listed by MedlinePlus, along with rare diarrhea, loose stools and stomach cramps. The trials on this page reported no adverse events. Sun sensitivity has been reported with chlorella tablets that contained the breakdown product pheophorbide a, and with abalone guts. But we found no case with chlorophyllin tablets.
Is chlorophyll good for your blood?
Chlorophyll’s ring resembles the heme in blood, but it holds magnesium, not iron, and the resemblance does not show that it builds blood. Wheat grass tablets did not lower transfusion needs in 53 people with thalassemia major, while a small uncontrolled pilot saw 8 of 16 improve. A Chinese tablet containing sodium iron chlorophyllin raised hemoglobin in a 39-trial meta-analysis, but its iron may explain that.