Li Zhi He (Leechee Nut)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Li Zhi He?

  9–15 g in decoction, crushed before dispensing (Bensky), with Chen & Chen giving 10–15 g. The two ranges agree closely, which is not always the case. The crushing instruction on our record is the operative detail: a lychee pit is a hard, dense, water-resistant seed, and an intact one gives up very little to a decoction — the same reason Ju He is broken before use.

  • Decoction — 9–15 g (Bensky) or 10–15 g (Chen & Chen), crushed.
  • Processing — the seed is commonly dry-fried before use, as hard seeds in this group generally are. Recorded as classical processing that exists, not as a home preparation instruction.
  • Compared with Ju He — our Ju He record gives 3–10 g, so Li Zhi He is dosed noticeably higher. Both are crushed; neither is a small-dose herb.

  Source: Sacred Lotus sources & references (the recorded ranges and the crushing note for Li Zhi He, and the recorded range for Ju He, attributed as held on file to Bensky and Chen & Chen). Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Li Zhi He?

  Yes — our record gives a pattern caution: use with caution in patients who are not suffering from cold-damp qi obstruction. That follows directly from its nature. A warm, cold-dispersing, qi-moving seed given where there is no cold and nothing stagnant has nothing useful to do and can aggravate heat.

  • Heat patterns and yin deficiency — the general caution for warm, dispersing herbs; this is the practical reading of our recorded caution.
  • Testicular pain is a presentation that needs assessment. A reference note about the setting rather than the herb: sudden or severe testicular pain, and any new groin swelling, are situations for prompt conventional medical evaluation. The traditional indications are documented here as reference facts, not as instructions for use.
  • Pregnancy — no specific traditional prohibition is recorded for Li Zhi He on this site. Qi-moving and warming herbs are conventionally used in pregnancy only under professional supervision.
  • Blood glucose — lychee seed extracts have repeatedly lowered blood glucose in animal models (see research), and the seed contains two amino acids that are documented causes of hypoglycaemia (see toxicity). Anyone with diabetes, or taking glucose-lowering medication, has a clear reason to raise this herb with their prescriber. Precautionary.
  • Sapindaceae relatives — anyone who reacts to lychee, longan or rambutan should treat the seed as the same botanical source.

  Source: Sacred Lotus sources & references (recorded cautions entry, as held on file); category cautions per published materia medica consensus, cross-referenced against multiple online sources; glucose and constituent points per the research and toxicity sections below. Reference note, not a safety guarantee.

Chinese Herb Toxicity & Overdose

• Is Li Zhi He safe? What about the lychee encephalopathy outbreaks?

  Our record says “very well tolerated,” and no report of poisoning from medicinal Li Zhi He could be found. But this herb needs a precise answer rather than a reassuring one, because lychee is genuinely associated with a documented, fatal childhood illness — and the honest position is that the outbreak evidence concerns the fruit while the laboratory chemistry also concerns the seed. Here is exactly what is established, and exactly where each finding belongs.

  • What happened, and to whom — the fruit. Recurrent outbreaks of acute hypoglycaemic encephalopathy in young children in Muzaffarpur, India, were investigated in a case-control study published in 2017. Illness was associated with visiting lychee orchards and eating lychees, and with not eating an evening meal; affected children had low blood glucose and abnormal fatty-acid metabolism, and urinary metabolites of two soapberry-family amino acids — hypoglycin A and methylenecyclopropylglycine (MCPG) — were found in the great majority of cases and in essentially none of the controls (PMID 28153514; DOI 10.1016/S2214-109X(17)30035-9). These toxins block fatty-acid oxidation, so a child whose glycogen is already exhausted by an absent evening meal cannot maintain blood glucose overnight. Undernutrition and an empty stomach are part of the causal picture, not incidental (PMID 32511708; PMID 39074693). Unripe fruit carries higher toxin levels (PMID 37442293).
  • The toxins are also present in the seed — and at far higher concentrations. This is the part that cannot be waved away. A US Centers for Disease Control and Prevention laboratory extended its method from fruit aril to seed and reported the first quantitation of hypoglycin A in litchi seeds, alongside MCPG. Across sample groups, seed MCPG ranged from roughly 8.7 to 3420 µg/g and seed hypoglycin A from roughly 2.6 to 267 µg/g (PMID 29853400; PMC 5985522). For scale, an independent analysis of lychee aril from three Chinese cultivars found MCPG at 0.08–0.83 mg/kg and hypoglycin A at 0.35–14.46 mg/kg — the same units (PMID 32454275). Different laboratories and different fruit, so these are not a controlled comparison, but the order of magnitude is not in doubt: the seed is the toxin-rich part, not the flesh.
  • What has not been shown. No case of hypoglycaemic encephalopathy, or of any poisoning, has been attributed to Li Zhi He used as a medicinal. No study has measured what happens to these amino acids during the dry-frying and decoction the medicinal seed undergoes, or what proportion of them ends up in a strained decoction. That gap is real and we are not going to fill it with an assumption in either direction.
  • The reasonable reading. The documented harm involved undernourished young children eating quantities of fresh fruit, chiefly unripe, in place of meals — not adults taking a crushed, cooked seed in a compound decoction under supervision. That is a genuine difference in exposure, and it is the most likely reason a long traditional record shows no comparable reports. It is not a demonstration of safety, and the seed’s measured chemistry means this is a herb for professional supervision rather than casual self-dosing — particularly in children, in anyone undernourished or fasting, and in anyone with unstable blood glucose.

  Discrepancy flagged: our record’s toxicity entry reads “very well tolerated,” reflecting the traditional clinical record, while the analytical literature shows the raw seed to be the most toxin-concentrated part of the fruit. We regard both as accurate about different things — clinical experience of the prepared medicinal versus measured chemistry of raw material — and have left the recorded entry unchanged, setting the published measurements alongside it rather than overwriting it. This is an owner decision.

  Sources: Sacred Lotus sources & references (recorded toxicity entry, as held on file); PMID 28153514, DOI 10.1016/S2214-109X(17)30035-9 (Muzaffarpur case-control study); PMID 32511708, PMID 39074693, PMID 37442293 (reviews of aetiopathogenesis, mechanism, and unripe-fruit toxicity); PMID 29853400, PMC 5985522 (first quantitation of hypoglycin A and MCPG in litchi seeds); PMID 32454275 (MCPG and hypoglycin A in litchi aril of three Chinese cultivars); PMID 27367968, PMC 5098216 (first report of hypoglycin A in litchi aril). Neutral reference facts — not a safety guarantee, not medical advice, and not a usage instruction.

Herb-Drug Interactions

• Does Li Zhi He interact with medications?

  No clinical herb–drug interaction has been documented for Li Zhi He, but there is one flag a practitioner should carry: blood glucose. Two independent lines of evidence point the same way. Lychee seed extracts and their isolated polyphenols have lowered blood glucose and improved insulin resistance across a substantial preclinical literature (see research). Separately, the seed contains hypoglycin A and MCPG, amino acids whose defining documented effect in humans is severe hypoglycaemia (see toxicity). These are different phenomena at very different exposures, and neither is evidence of a clinical interaction — but both concern glucose, and they converge.

  • Glucose-lowering medication — insulin, sulfonylureas and other antidiabetic drugs are the obvious point of caution. Additive hypoglycaemia is a theoretical rather than a reported effect for this herb; it warrants monitoring and a conversation with the prescriber, not alarm.
  • Fasting, illness and children — the outbreak literature makes clear that an empty stomach and depleted glycogen are what turn these compounds dangerous. Practitioner awareness in fasting, undernourished or paediatric patients is reasonable on that basis alone.
  • What has not been measured — no enzyme-inhibition study and no human pharmacokinetic study of Li Zhi He with any medicine could be found.

  (Precautionary, based on constituent class and preclinical findings; flagged for practitioner confirmation.)

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Li Zhi He (Semen Litchi Chinensis)?

  Yes, and there is a lot of it — but none of it is about hernia or groin pain, and none of it is clinical. The modern literature on lychee seed runs almost entirely along two tracks that the tradition never mentions: blood glucose and liver fibrosis. Treat all of it as context, not as efficacy.

  • Blood glucose and insulin resistance — a review from a Chinese Academy of Chinese Medical Sciences endocrinology department gathers the antihyperglycaemic work on lychee seed, its extracts and its isolated compounds — including quercetin, procyanidin A2 and a naringenin glycoside — across improvement of insulin resistance, anti-inflammatory effect, lipid regulation, neuroprotection and renal protection (PMID 34690773; PMC 8531476; DOI 10.3389/fphar.2021.737803). Underlying studies include metabolomic profiling of polyphenol extracts in type 2 diabetic rats (PMID 28793771) and a study of effective constituents on insulin resistance in the same model (PMID 26946845).
  • Neuroprotection via the same mechanism — lychee seed polyphenols reduced Alzheimer’s-associated Tau phosphorylation by improving insulin resistance through the IRS-1/PI3K/Akt/GSK-3β pathway (PMID 31917277), lychee seed saponins protected PC12 cells from amyloid-beta-induced apoptosis (PMID 28353652; PMC 5409676), and seed extract improved cognitive measures in diabetic rats with cognitive impairment (PMID 29138799). Cell and animal work throughout — and notably the same insulin-resistance thread as the Ju He neuroprotection literature, arrived at from a different plant family.
  • Liver fibrosis — the total flavonoids of lychee seed have been studied repeatedly against fibrosis: in carbon-tetrachloride-induced fibrosis in rats, linked to retinol metabolism (PMID 35787093); in schistosomiasis-associated fibrosis in mice (PMID 39094546); against liver damage from Clonorchis sinensis infection (PMID 40809521); and via inhibition of PANoptosis (PMID 41361707). The authors describe lychee seed as a traditional treatment for liver fibrosis in China — a use our own record does not carry.
  • Authentication — multiplex PCR markers based on internal transcribed spacer sequences were developed to distinguish authentic Litchi Semen and Longan Arillus from substitutes, the authors noting that adulteration among these Sapindaceae products is economically motivated (PMID 32731322; PMC 7464683).
  • Toxin chemistry — the hypoglycin A and MCPG measurements in seed and aril are covered in the toxicity section above and are the most consequential published findings about this material.

  Honest summary: the traditional indication — cold-type hernial and testicular pain — is untested by modern research. The glucose and liver-fibrosis literature is real, substantial for a minor herb, and entirely preclinical; it demonstrates nothing clinically and is reported here as context. The most solid published facts about lychee seed remain its chemistry, not its pharmacology.

  Sources: PMID 34690773, PMC 8531476, DOI 10.3389/fphar.2021.737803 (review of hypoglycaemic activity and mechanisms); PMID 28793771 (metabolomics in type 2 diabetic rats); PMID 26946845 (effective constituents on insulin resistance); PMID 31917277 (Tau and insulin resistance via IRS-1/PI3K/Akt/GSK-3β); PMID 28353652, PMC 5409676 (seed saponins against amyloid-beta-induced apoptosis); PMID 29138799 (cognitive function in diabetic rats); PMID 35787093 (anti-liver-fibrosis effects of total flavonoids); PMID 39094546 (schistosomiasis liver fibrosis); PMID 40809521 (Clonorchis sinensis-induced liver damage); PMID 41361707 (hepatic fibrosis and PANoptosis); PMID 32731322, PMC 7464683 (multiplex PCR identification of Litchi Semen). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Li Zhi He different from Ju He?

  They are the two seeds in the qi-regulating chapter, they share almost the same indication, and they are classically used together — but Li Zhi He is warm and Ju He is neutral, and that is the difference that decides which one a pattern calls for. Both are seeds of common food fruits; neither is a digestive herb; both aim at the groin and the Liver channel’s course.

  • Li Zhi He (this page, Semen Litchi Chinensis) — lychee seed; sweet, astringent, warm; Liver and Stomach. Because it is warm it disperses cold, which is why our record cautions against using it where there is no cold-damp qi obstruction to disperse.
  • Ju He (Semen Citri Reticulatae) — tangerine seed; bitter, neutral. Same hernial and testicular brief, plus breast pain and nodules. It is the chief herb of Ju He Wan, the formula built around exactly this pattern.

  How they are used together: the pairing is a standard one for cold-type hernial disorder — Li Zhi He brings the warmth and the cold-dispersing action, Ju He brings the qi-moving and clump-dissipating action, and neither is asked to do the other’s job. Where the presentation is clearly cold and painful, Li Zhi He leads; where it is a mass or nodule without a cold sign, Ju He does.

  Botanically they are not close relatives. Ju He comes from a citrus, in the rue family; lychee is in the soapberry family (Sapindaceae), alongside longan and rambutan. That family membership is not trivia — it is the reason for the toxicity section on this page.

  Adulteration note: lychee seed and longan aril are both traded Sapindaceae products with similar-looking material, and DNA markers have been developed specifically to tell authentic Litchi Semen from substitutes, the authors noting that adulteration in this group is economically motivated (PMID 32731322; PMC 7464683).

  Formula context: our own formula records do not currently link Li Zhi He to any formula, so no formula is named here.

  Source: Sacred Lotus sources & references (the herb records for Li Zhi He and Ju He — nature, flavour, channels, category, dosage and recorded cautions — and the Ju He Wan formula record, as held on file); published materia medica consensus for the pairing, cross-referenced against multiple online sources; authentication per PMID 32731322. Comparison note, not treatment advice.