CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-18). The draft was written by AI, the existence of all 4 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 517 · Search date 2026-07-18 · Methodology v0.6

Polygonum multiflorum,
does it really help with Improvement of hair loss and restoration of gray hair to black?

30-Second Summary
?
Evidence Grade ? · Safety unknown
Traditional black-hair use and preclinical signals exist, but direct human efficacy trials do not
What the
research shows
No credible human efficacy trial was found testing oral Polygonum multiflorum alone for hair loss improvement or restoration of gray hair to black. The identified hair evidence consists of cultured human dermal papilla cells, ex vivo follicles, and mouse studies. Traditional use for darkening hair is not a clinical trial, so the verdict is unknown. Separately from efficacy, oral Polygonum multiflorum has been linked to numerous cases of liver injury and warrants strong safety caution.
What the
ads claim
Marketing connects the name and traditional black-hair story to proven human hair regrowth or melanin restoration. Traditional use and preclinical mechanisms are not clinical evidence for treating alopecia or reversing gray hair.
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Useful facts when choosing a product

  • The Korean pharmacopoeial herb is the tuberous root of Polygonum multiflorum Thunberg and is botanically distinct from Cynanchum wilfordii, commonly called baek-su-o.
  • It may be sold in South Korea as crude herb, pills, powder, concentrates, or tea, but no validated oral human dose exists for hair loss or repigmentation.
  • Raw and processed roots, extraction solvents, and marker-compound concentrations differ, so products cannot be assumed equivalent.
  • Oral Polygonum multiflorum has been associated with many liver-injury cases, including jaundice and marked enzyme elevation, and injury has also occurred with processed products. People with liver disease or hepatotoxic medicines require particular caution.
Gap Measurement · Verdict 517 · ?
What advertising claims
What independent, higher-quality research supports
△ GAP
01

What the research actually shows

Li 2015 gave raw or processed Polygonum multiflorum orally or topically to C57BL/6J mice and assessed coat coverage, length, follicle number, and color. Shin 2020 studied anagen-related pathways in cultured human dermal papilla cells and ex vivo follicles. A 2026 study likewise remained at cell and ex vivo human-follicle level. Reviews of human Polygonum multiflorum literature primarily identify pharmacokinetic work, other indications, and hepatotoxicity reports; no controlled oral trial directly testing hair loss or gray-hair reversal was identified.

02

Why this is classified as ?

Hair-related cell and animal work and traditional use exist, but no oral human efficacy trial for hair loss or gray hair was identified. Preclinical-only evidence does not justify forcing a D grade when the human literature is absent, so the verdict is unknown with a null score.

Counterpoint. Preclinical signals justify a hypothesis for a standardized, safety-monitored human trial, not a current recommendation to take the herb.

Rejudgment record. New verdict — No oral human efficacy trial for hair loss or gray-hair reversal; cell, animal, and traditional-use evidence cannot establish human efficacy

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Hair-loss improvement or hair growth with oral Polygonum multiflorum?Only cell, ex vivo follicle, and mouse evidence was identified, without a direct human efficacy trial.
Restoration of gray hair to black?Beyond traditional use and animal coat-color observations, no human hair-repigmentation trial was identified.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Li Y et al. 2015Preclinical mouse study6Chinese research fundingHair coverage, length, follicle number, and coat colorReported hair-growth and color-related signals with raw or processed root, but the study did not involve humans.Preclinical
Shin JY et al. 2020Cultured-cell and ex vivo follicle studyInvestigators affiliated with LG Household and Health CareAnagen-related signaling and follicle lengthReported signals consistent with anagen prolongation, but this was not a clinical trial administering the product to people.Preclinical
Bounda GA, Feng YU. 2015Review of clinical literatureAcademic reviewScope of human researchHuman pharmacokinetic, other-indication, and safety literature existed, but no direct oral hair-loss or repigmentation trial was presented.Confirms gap
Lei X et al. 2015Systematic review of liver-injury case reports and series450Academic research fundingLiver injury associated with Polygonum multiflorumSynthesized 450 cases, including two liver transplants and seven deaths.Safety
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Receipt — 4 References

All 4 cited sources were verified for existence at the original page (as of 2026-07-18).

Li Y, Han M, Lin P, He Y, Yu J, Zhao R. Hair growth promotion activity and its mechanism of Polygonum multiflorum. Evid Based Complement Alternat Med. 2015;2015:517901. PMID: 26294926. DOI: 10.1155/2015/517901.
checked
Shin JY, Choi YH, Kim J, Jin MH, Lee S. Polygonum multiflorum extract support hair growth by elongating anagen phase and abrogating the effect of androgen in cultured human dermal papilla cells. BMC Complement Med Ther. 2020;20:144. PMID: 32398000. DOI: 10.1186/s12906-020-02940-5.
checked
Bounda GA, Feng YU. Review of clinical studies of Polygonum multiflorum Thunb. and its isolated bioactive compounds. Pharmacognosy Res. 2015;7(3):225-236. PMID: 26130933. DOI: 10.4103/0974-8490.157957.
checked
Lei X, Chen J, Ren J, et al. Liver damage associated with Polygonum multiflorum Thunb.: a systematic review of case reports and case series. Evid Based Complement Alternat Med. 2015;2015:459749. PMID: 25648693. DOI: 10.1155/2015/459749.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-18 · Corrections: none

Cite this verdict

Polygonum multiflorum x hair loss and reversal of gray hair Evidence Grade ? card
[Chamgap] Polygonum multiflorum x hair loss and reversal of gray hair — Evidence Grade ?. 4 cited sources checked. Source: https://chamgap.com/en/verdicts/skin-hair/polygonum-multiflorum-hair-loss-gray-hair/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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What this document does and does not do

Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.