Epicatechin

Epicatechin is a flavanol, a plant compound in the flavonoid family, and a major flavanol in cocoa. In cocoa it occurs alone and in chains of up to ten linked units. EU rules count them all as “cocoa flavanols.”

Plants make related compounds called tannins to defend themselves, according to a 2022 review. They guard against pathogens, plant-eating insects and stress from light and wounds.

In the USDA data on this page, cocoa powder holds the most epicatechin, 196 mg per 100 g. Even so, older Dutch men got most of theirs from tea (51%) and apples (28%), and only 7% from cocoa.

One thing most readers do not know is that epicatechin has close relatives that behave differently. When healthy men drank four related flavanols at the same dose, only (-)-epicatechin, the form in cocoa, clearly widened their arteries.

A second surprise is the evidence itself. Nearly all human trials used cocoa, which is a mixture, so they say little about epicatechin alone. The few trials of pure epicatechin are small.

Processing matters too. The Kuna people of Panama’s San Blas islands drank flavanol-rich cocoa as their main drink, supplying more than 900 mg of flavanols a day. In one Spanish study, alkali (“Dutch”) processing cut the epicatechin in commercial cocoa powder by 67% on average. So ordinary chocolate and the flavanol-standardized extracts used in the biggest trial are not the same thing.

Health benefits of epicatechin

• ★★★Healthy blood vessel widening from cocoa flavanolsThe EU authorizes a health claim that 200 mg a day of cocoa flavanols (not epicatechin alone) keeps blood vessels widening normally. In 42 short trials, cocoa raised artery widening by 1.34% after repeated intake.
• ★★Slightly lower blood pressureIn 35 trials, flavanol-rich cocoa lowered the top and bottom blood pressure numbers by 1.76 mm Hg each. A pool of 145 trials of flavan-3-ol products such as cocoa, tea and apples found drops of 2.8 and 2.0 mm Hg (top and bottom).
• ★★Lower insulin resistance with cocoa flavanolsIn 19 trials, cocoa flavanols cut fasting insulin by 2.33 μIU/mL and insulin resistance (HOMA-IR) by 0.93. A review of 42 cocoa trials found a smaller drop in insulin resistance (HOMA-IR fell 0.67).
• ★★No clear drop in heart eventsIn 21,442 older adults, a cocoa extract (500 mg of flavanols a day) gave 0.90 times the risk of heart events, which could be chance. Cardiovascular death was 27% lower, a secondary result.
• ★★Mixed results for thinking skillsIn 2,262 older adults, a cocoa extract had no effect on global thinking scores over 3 years. A pool of 16 trials found some thinking tests improved, but not the Mini-Mental State Exam.

Foods high in epicatechin

In the USDA data on this page, cocoa powder is the richest source at 196 mg of epicatechin per 100 g. Green tea comes next at 8.33 mg, then apples, cherries and apricots.

Nobody eats 100 g of cocoa powder, so servings tell a different story. A cup of green tea gives 20.4 mg, a medium apple 13.7 mg and a tablespoon of cocoa powder 10.6 mg. A cup of cherries gives 7.7 mg and a medium pear 6.69 mg.

Real diets run on tea and fruit. Older Dutch men averaged 15.2 mg a day, 51% from tea, 28% from apples and 7% from cocoa. In a large European study, apples and pears were the top source of flavan-3-ols outside the UK, where tea led.

Cocoa powders vary a lot: Spanish brands held 11.6 to 73 mg of epicatechin per 100 g. Alkali processing cut it by 67% on average, probably in part by turning it into (-)-catechin, which is less well absorbed. The USDA figure may not describe every product.

How epicatechin works

Most of what we know about how epicatechin works comes from cells, isolated arteries and animals, plus a few small human tests. Researchers point to four ideas.

It helps blood vessels make nitric oxide, and only one mirror-image form of it seems to work. It may switch on muscle and mitochondria signals, and the body rewrites it before it acts. Here is each one, and what has been seen in people.

It helps blood vessels make nitric oxide

Nitric oxide is made in the lining of blood vessels and helps them widen. That is how a Cochrane review explains cocoa’s effect on blood pressure. In human coronary artery cells, (-)-epicatechin switched on eNOS, the enzyme that makes it, even when calcium, the usual trigger, was removed. In isolated dog arteries, a blocker of the enzyme stopped the signal that leads to relaxation.

In people the picture is partly the same. After flavanol-rich cocoa, healthy men had more circulating nitric oxide species and wider arteries, and blocking the enzyme removed the artery effect. A single 200 mg dose of (-)-epicatechin raised nitric oxide markers in 12 men.

Not every test agrees. After 4 weeks of 100 mg a day, nitric oxide did not change. A dose study saw only changes in nitrite and nitrate that could be chance.

Only one mirror-image form seems to work

Flavanols come in four closely related shapes: (-)-epicatechin, (+)-epicatechin, (-)-catechin and (+)-catechin. Healthy men took each at 1.5 mg per kg of body weight. Blood and urine levels differed a lot between the forms, and only (-)-epicatechin clearly widened arteries.

The widening did not depend on flavanols’ classic antioxidant properties. Catechin has its own catechin page.

The tea catechin EGCG did not behave like epicatechin either. In a crossover trial of 12 men, 200 mg of EGCG changed none of the nitric oxide measures that (-)-epicatechin raised. EGCG has its own EGCG page.

It may switch on muscle and mitochondria signals

Mitochondria are the cell’s power plants. In mice, 15 days of (-)-epicatechin raised treadmill performance by about 50%. Muscle fatigue resistance rose by about 30%, with more mitochondrial proteins and more capillaries.

In 7 adults with Becker muscular dystrophy, 8 weeks of 50 mg twice a day raised muscle follistatin and a mitochondria-building signal. It lowered myostatin, a brake on muscle growth. There was no placebo group.

A second route is Nrf2, a switch for the cell’s own antioxidant enzymes. In muscle samples from the cocoa trial in peripheral artery disease, rises in Nrf2-driven enzymes went with fewer signs of muscle damage. Epicatechin also protected human muscle cells from patient serum. These findings come from a single trial and from cells.

The body rewrites it before it acts

Epicatechin is changed on its way through the body, in part by gut bacteria. A 2023 review of 49 human studies counted up to 180 metabolites in blood and urine, mostly conjugates of smaller compounds made by gut bacteria.

Mean bioavailability (the share absorbed) of flavan-3-ols was 31 ± 23%. It was about 82% after (-)-epicatechin in one study, and about 25% after tea, cocoa or apples.

In the 2006 cocoa study, (-)-epicatechin and its metabolite epicatechin-7-O-glucuronide best predicted the artery effect. Which circulating compounds do the work is still being sorted out.

What has been seen in people

The human data fit the mechanisms only loosely. Meta-analyses of cocoa flavanols found flow-mediated dilation up by about 1.2 to 1.5 percentage points. Systolic pressure fell by about 1.6 to 2.7 mm Hg, which are small effects.

Pure epicatechin at 100 mg a day did not clearly change flow-mediated dilation, and the COSMOS extract missed its main heart goal. The muscle findings come from open-label studies of 5 to 7 people. All of these are among the study cards above.

Is epicatechin safe? Supplements, dose and interactions

Eating epicatechin in tea, apples and cocoa is routine: older Dutch men took in about 15 mg a day. The EU health claim for cocoa flavanols (200 mg a day) is a statement about benefit, not a safety limit.

We found no acceptable daily intake or upper level for epicatechin or cocoa flavanols. The US FDA list of GRAS (“generally recognized as safe”) notices has no entry for epicatechin, flavanols or cocoa extract.

• Trial doses and side effects. COSMOS gave 500 mg of cocoa flavanols (80 mg of epicatechin) for a median of 3.6 years with no safety concerns. Up to 2,000 mg a day for 12 weeks was well tolerated. A Cochrane review found nausea or stomach upset in 1% of people on cocoa and 0.4% on control. Pure epicatechin has been tested at 100 mg a day for 4 weeks and 50 mg twice a day for 8 weeks, in small trials.
• Iron. Cocoa and tea drinks cut absorption of non-heme iron (the type in plant foods) from a bread meal. A cocoa drink cut it by 71%, and drinks with 100 to 400 mg of polyphenols cut it by 60 to 90%. That was measured for whole drinks, not epicatechin alone. The authors say it should be considered in iron advice. So people with low iron may want to ask a doctor about cocoa and tea with meals.
• Heavy metals in cocoa products. Of 72 US dark chocolate and cocoa products, 43% were above California’s Prop 65 limit for lead in a single serving. 35% were above its limit for cadmium. Even so, 70 of 72 were under the FDA’s reference level for lead. Organic products were more likely to have higher levels of both. An earlier US analysis found cadmium and lead rising with the percentage of cocoa solids.
• Pregnancy, medicines and conditions. We found no safety trials of epicatechin supplements in pregnancy or breastfeeding, and no drug interaction studies, so ask your doctor. Cocoa flavanols lowered blood pressure by a few mm Hg in trials. So people on blood pressure medicine should mention a new supplement.

How to get more epicatechin

• Best foods. Per serving, a cup of green tea leads the USDA ranking (20.4 mg). A medium apple (13.7 mg) and a tablespoon of cocoa powder (10.6 mg) follow.
• Skip the alkali. Dutch-processed cocoa lost 67% of its epicatechin on average, so look for natural, non-alkalized cocoa. In the 2008 Spanish survey, brands ranged from 11.6 to 73 mg per 100 g.
• Food versus extract. The 80 mg of epicatechin in the COSMOS extract equals about 41 g of USDA cocoa powder. It also equals 4 cups of green tea or 6 medium apples. One review found absorption of 82% after pure epicatechin in a single study, against about 25% from tea, cocoa or apples. But in a crossover trial, the bioavailability of epicatechin did not differ between capsules and dark chocolate.

History of epicatechin

The modern story starts with an island people. The Kuna of Panama’s San Blas islands had little age-related rise in blood pressure, and the rise appeared when they moved to Panama City.

Island Kuna drank more than 5 cups of flavanol-rich cocoa a day, while mainland Kuna drank little. Island dwellers had a three-fold higher urinary nitrate-to-nitrite ratio, a sign of more nitric oxide. Death certificate data showed far fewer deaths from heart disease and cancer on the islands, though the researchers noted this could not prove cause.

In 2006 a research team gave healthy men flavanol-rich cocoa. They identified (-)-epicatechin as the compound best linked to the artery response. In 2011 a follow-up compared four related flavanols and found that only (-)-epicatechin clearly widened arteries. The catechin family takes its name from catechu, the tannin-rich juice of an acacia tree.

Regulators and big trials came next. In July 2012 EFSA concluded that a cause-and-effect link had been shown between cocoa flavanols and maintaining normal artery widening. The EU authorized the claim in 2013, protecting one proprietary study for five years.

COSMOS, a trial of 21,442 older adults, ran its intervention from June 2015 to December 2020. In 2022 it reported that the cocoa extract did not clearly reduce total cardiovascular events.

Frequently asked questions about epicatechin

What does epicatechin do for the body?

Its best-supported effect is on blood vessels. In meta-analyses of cocoa flavanols, flow-mediated dilation rose about 1.2 to 1.5 percentage points. Systolic blood pressure fell 1.6 to 2.7 mm Hg, and the EU approved a claim for 200 mg of cocoa flavanols a day. But these trials used cocoa, not pure epicatechin. The biggest trial, COSMOS, did not clearly cut heart events, and muscle findings come from tiny studies.

Which foods are high in epicatechin?

Cocoa powder leads the USDA ranking at 196 mg per 100 g. Then come green tea at 8.33 mg, apples at 7.53 mg and cherries at 5 mg. Per serving, a cup of green tea gives 20.4 mg, a medium apple 13.7 mg and a tablespoon of cocoa powder 10.6 mg. Alkali-processed cocoa holds far less, 67% less on average in one study.

How much epicatechin should you take a day?

No dose is proven best. The EU claim is for 200 mg a day of cocoa flavanols, and COSMOS used 500 mg of flavanols with 80 mg of epicatechin. Pure epicatechin trials used 100 mg a day or 50 mg twice a day. A dose analysis put the best vessel effect at about 95 mg of epicatechin. We found no official upper level, so talk to a clinician before going higher.

Does epicatechin have side effects?

Trials report few. Up to 2,000 mg of cocoa flavanols a day for 12 weeks caused only mild side effects that did not differ from control. COSMOS found no safety concerns over 3.6 years. Cocoa drinks can block iron absorption, and some cocoa products carry lead and cadmium; we found no safety trials in pregnancy.

Does epicatechin lower blood pressure?

Slightly, as part of cocoa. A Cochrane review of 35 trials found both blood pressure numbers down by about 1.8 mm Hg. A 2026 analysis found 2.7 and 1.8 mm Hg. In 37 people, 100 mg of pure epicatechin a day for 4 weeks did not change blood pressure. The drop was bigger when starting pressure was high.

What is the difference between epicatechin and catechin?

They are closely related flavanols that differ in the three-dimensional arrangement of their atoms, and the body handles them differently. In healthy men, only (-)-epicatechin clearly widened arteries, and blood levels of the four forms differed. Alkali processing of cocoa can turn (-)-epicatechin into (-)-catechin, a less well absorbed form. See the catechin page.

Epicatechin vs EGCG: which is better?

Neither has been shown better overall. In a crossover trial of 12 men, 200 mg of epicatechin raised nitric oxide markers while 200 mg of EGCG changed none. Large flavan-3-ol analyses mix both, along with cocoa and tea. See the EGCG page.

Does epicatechin build muscle?

Not proven. In mice, 15 days of (-)-epicatechin raised treadmill performance by about 50%. In 7 adults with Becker muscular dystrophy, 50 mg twice a day for 8 weeks changed muscle markers, with no placebo group. A 7-day trial reported higher hand grip strength, but its abstract gives no size or dose.