Lychee
A tropical fruit that's a strong vitamin C source — about 10 lychees provide ~50% DV. A real but specific safety signal: unripe lychee contains hypoglycin A and MCPG, which can cause life-threatening hypoglycemic encephalopathy in undernourished, fasting children. This caused recurrent outbreaks in Muzaffarpur, India that killed >100 children some seasons. The fix is simple — eat ripe lychee with a proper meal. 'Oligonol' lychee-polyphenol supplements have only small manufacturer-affiliated trials.
Quick decision guide
May help most
Anyone enjoying lychee as a ripe fruit alongside meals. Avoid unripe lychee in children who haven't eaten properly.
Common dosing range
10–15 ripe lychees (~100 g pulp) is a normal serving — ~66 kcal, ~80% DV vitamin C. Oligonol supplement trials used 100–200 mg/day.
When to expect effects
Nutritional benefits with regular intake. Oligonol metabolic effects (visceral fat, CRP) in published trials were measured at 10+ weeks; effect sizes small.
Watch out for
Unripe lychee on an empty stomach in malnourished children → acute hypoglycemic encephalopathy. Don't let kids snack on green/unripe lychees in place of a meal. As an adult eating ripe lychee with meals, this is not your risk.
Evidence snapshot
What is it
Lychee is a plant-derived ingredient sold as a dietary supplement and used in traditional herbal use. Found on roughly 897 U.S. supplement labels.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Vitamin C and copper from a tropical fruit Strong Evidence | 10 lychees ≈ 80% DV vitamin C, 16% DV copper, ~66 kcal | Adults wanting a high-vitamin-C tropical fruit and a low-calorie snack | Vitamin C status improves within days of adequate intake |
Oligonol (lychee polyphenol) for visceral fat / metabolic markers Mixed Evidence | Small reductions in visceral fat area and CRP in a single 10-week RCT (n=31) | Adults experimenting with Oligonol for metabolic health alongside diet and exercise | 10+ weeks in trials |
Polyphenol antioxidant capacity (mechanism only) Mixed Evidence | In vitro antioxidant activity; no clinical endpoint data | None established | Not established |
Vitamin C and copper from a tropical fruit
- Effect
- 10 lychees ≈ 80% DV vitamin C, 16% DV copper, ~66 kcal
- Best fit
- Adults wanting a high-vitamin-C tropical fruit and a low-calorie snack
- Time
- Vitamin C status improves within days of adequate intake
Oligonol (lychee polyphenol) for visceral fat / metabolic markers
- Effect
- Small reductions in visceral fat area and CRP in a single 10-week RCT (n=31)
- Best fit
- Adults experimenting with Oligonol for metabolic health alongside diet and exercise
- Time
- 10+ weeks in trials
Polyphenol antioxidant capacity (mechanism only)
- Effect
- In vitro antioxidant activity; no clinical endpoint data
- Best fit
- None established
- Time
- Not established
Evidence for 3 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Vitamin C and copper from a tropical fruit
Per USDA, 100 g of raw lychee (about 10 fruits, pulp only) provides ~72 mg vitamin C (~80% DV), 0.15 mg copper (~16% DV), and 171 mg potassium for 66 kcal. Lychee is among the more vitamin-C-dense tropical fruits, comparable to a small orange. Polyphenols (proanthocyanidins) and small amounts of folate round out the profile.
Bottom line: A solid vitamin C source — enjoy as ripe fruit, with a meal.
Oligonol (lychee polyphenol) for visceral fat / metabolic markers
Supplement benefitOligonol is a proprietary lychee-seed polyphenol mixture standardized by Amino Up Chemical (Japan). Nishizawa 2011 (n=31, 10 weeks, 100 mg/day) reported a small reduction in visceral fat area and CRP vs placebo in overweight adults. Sample sizes are small, trials are short, and most are conducted by the manufacturer or its academic collaborators. No independent large RCTs replicate the findings.
Bottom line: Niche product with weak independent evidence. Whole lychee is the more cost-effective way to get the same polyphenols.
Polyphenol antioxidant capacity (mechanism only)
Mechanism onlyLychee pulp and seed contain proanthocyanidins and other polyphenols that show antioxidant activity in lab assays. Translation to clinical outcomes in humans is unproven. Antioxidant capacity in a test tube is not a clinical endpoint.
Bottom line: Eat lychees as fruit. Don't pay extra for polyphenol-extract capsules on this basis.
How it works
How to take it
What to track
Bottom line: Eat ripe lychee with meals. ~10 lychees gives ~80% DV vitamin C. Skip the supplement-extract capsules.
5 commercial forms
Compare the main delivery options and what they’re best suited for.
Fresh ripe lychee (in season)
Best vitamin C + flavorPeel the pink-red shell, eat the white pulp, discard the seed. 10 lychees provide ~80% DV vitamin C for ~66 kcal. The benchmark form.
Whole-fruit fiber and water content; lowest glycemic impact among lychee forms.
Frozen lychee (whole or peeled pulp)
Year-round vitamin CQuick-frozen retains most vitamin C and polyphenols. Convenient for smoothies, desserts, and out-of-season use.
Comparable to fresh; freezing preserves vitamin C better than canning.
Canned lychee in light syrup
Added sugarConvenient and shelf-stable. Vitamin C is partially degraded by heat processing. Drain and rinse to reduce sugar load.
Lower vitamin C than fresh; higher glycemic load.
Oligonol (lychee polyphenol) capsules
Weak evidenceProprietary Japanese product (Amino Up Chemical). Small short manufacturer-affiliated RCTs suggest modest visceral fat and CRP effects. Not independently replicated at scale.
Designed for absorption (low-molecular-weight oligomers); clinical translation is small.
Dried / candied lychee
Treat as candyConcentrated sugar, much lower vitamin C, low fiber. Enjoy as an occasional treat — not a substitute for fresh fruit.
High glycemic load; minimal vitamin C.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
UNRIPE-LYCHEE HYPOGLYCEMIC ENCEPHALOPATHY: hypoglycin A and methylenecyclopropylglycine (MCPG) in unripe lychee block fatty-acid oxidation and gluconeogenesis. In undernourished fasting children — classically those who skipped dinner — large quantities can cause severe overnight hypoglycemia, seizures, coma, and death. Caused recurrent outbreaks in Muzaffarpur, India (>100 child deaths some seasons). Prevention: ensure children eat a proper evening meal; do not let kids substitute lychee snacks for meals; avoid green/unripe lychee. The toxin is highest in unripe fruit.
Acute hypoglycemia is uncommon in well-fed adults eating ripe lychee. The Muzaffarpur risk is the combination of unripe fruit + malnutrition + skipped meal. Adult overdoses on supplements are not known to cause this syndrome.
Lychee allergy (urticaria, oral allergy syndrome, rarely anaphylaxis) has been reported, particularly in people with latex or sunflower-seed allergies. Avoid if you've reacted before.
Who should avoid it
- Children eating unripe lychee on an empty stomach in lychee-growing regions — never substitute a snack for an evening meal. The hypoglycemic encephalopathy syndrome is essentially preventable with adequate nutrition.
- People with known lychee allergy or oral allergy syndrome (latex-fruit cross-reactivity).
- People with poorly-controlled diabetes — like other sweet fruits, watch portion size.
Pregnancy & breastfeeding
Ripe lychee in moderate amounts is safe during pregnancy as part of a varied diet. Wash thoroughly. Oligonol supplements lack pregnancy safety data and should be avoided.
Bottom line: Ripe lychee with meals is safe. Unripe lychee on an empty stomach in undernourished children can kill — this is the real, well-documented harm.
Interactions
Like any sweet fruit, lychee in large amounts can affect blood sugar. The MCPG/hypoglycin A unripe-lychee story is a separate severe hypoglycemia mechanism — not relevant to typical ripe-fruit intake.
Lychee contains a small amount of vitamin K. Typical fruit-serving intake should not destabilize INR; large changes in habitual fruit intake are worth mentioning to the anticoagulation clinic.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Lychee, raw — vitamin C | 100 g (~10 fruits, 72 mg) | 79% |
| Lychee, raw — copper | 100 g (0.15 mg) | 16% |
| Lychee, raw — potassium | 100 g (171 mg) | 4% |
| Lychee, raw — fiber | 100 g (1.3 g) | 5% |
| Lychee, raw — folate | 100 g (14 mcg) | 4% |
| Lychee, canned in syrup, drained | 100 g (~41 mg vitamin C) | 46% |
Lychee, raw — vitamin C
- Amount
- 100 g (~10 fruits, 72 mg)
- %DV
- 79%
Lychee, raw — copper
- Amount
- 100 g (0.15 mg)
- %DV
- 16%
Lychee, raw — potassium
- Amount
- 100 g (171 mg)
- %DV
- 4%
Lychee, raw — fiber
- Amount
- 100 g (1.3 g)
- %DV
- 5%
Lychee, raw — folate
- Amount
- 100 g (14 mcg)
- %DV
- 4%
Lychee, canned in syrup, drained
- Amount
- 100 g (~41 mg vitamin C)
- %DV
- 46%
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
What is Lychee used for?⌄
Lychee is used traditionally for various supportive purposes. Human evidence for specific health claims is generally limited, so it is best treated as a complementary option rather than a treatment.
Is Lychee safe?⌄
Lychee is generally well tolerated at typical doses, but quality varies between products. People who are pregnant, breastfeeding, taking prescription medications, or managing a medical condition should check with a healthcare provider first.
How long does it take to work?⌄
Effects of botanical supplements often take several weeks of consistent use, if they appear at all. Reassess after 8-12 weeks of regular use.
References by claim
Track Lychee with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.