{"ok":true,"entry":{"slug":"rehmannia","kind":"supplement","name":"rehmannia","aliases":["Rehmannia glutinosa","shu di huang","di huang"],"brands_sg":["Dragon Herbs"],"class":"botanical","tags":["general"],"use_for":"a tcm formula herb — little standalone human evidence","use_after":null,"use_duration":null,"take_with":null,"pros":["long use as the lead herb in classic tcm formulas","a 17-trial pooled review saw no severe adverse events","gut-microbiota and immune effects seen in lab studies"],"cons":["reviewers point plainly to a lack of human trials","that pooled review flags flaws and high heterogeneity","only one rehmannia product is listed on iherb sg"],"dose_note":"no rda, upper limit, fda daily value or hsa singapore daily limit exists for rehmannia; the 2026 review of rehmannia glutinosa polysaccharides states that clinical application still has to address 'the lack of human trials', so no human dose can be read from it; the only pooled human data found is 17 chinese randomised trials in 1,139 patients of multi-herb chinese medicine in which rehmannia was the principal (monarch) ingredient rather than the sole one, and that review itself flags methodological flaws and high heterogeneity; the single product listed on iherb singapore is a six-herb combination capsule, not a single-herb one","dosage":{"ul":null,"unit":null,"fda_dv":null,"rda_ai":null,"ul_status":"none_established","population":"general adult","hsa_max_daily":null},"ul_status":"none_established","sg_class":null,"cautions":["human data comes from multi-herb formulas, not from rehmannia on its own","that pooled data is in breast-cancer patients with perimenopausal symptoms, not general adults","no thorough human safety evaluation was found in the sources read","not listed in hsa's prohibited or restricted annexes — that is not a safety finding"],"clashes":[],"sources":[{"id":"rg_review","url":"https://europepmc.org/article/PMC/PMC13038584","label":"Rehmannia glutinosa polysaccharides: a review on structural features, pharmacological potential, and advanced delivery systems (Wang et al., Front Nutr 2026)","quote":"RGPs … exhibit diverse bioactivities including immunomodulation … Pharmacological studies show RGPs modulate gut microbiota … However, clinical application requires addressing batch variability, scalability, and the lack of human trials.","accessed":"2026-08-27"},{"id":"rg_pooled","url":"https://europepmc.org/article/PMC/PMC12251504","label":"Rehmannia glutinosa for perimenopausal syndrome in patients with breast cancer: A systematic review and meta-analysis (Saudi Med J 2025)","quote":"The meta-analysis included 17 RCTs involving 1,139 patients showing that CHM with Rehmannia glutinosa as the monarch drug … no severe adverse reactions were detected … the methodological flaws and high heterogeneity of the included RCTs.","accessed":"2026-08-27"},{"id":"hsa_prohibited","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA Singapore — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev. No. 001 (Oct 2025), Annex A (118 rows) and Annex B (4 rows) — rehmannia / Rehmannia glutinosa / shu di huang / di huang NOT LISTED in either annex","quote":"The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list.","accessed":"2026-08-27"},{"id":"hsa_hs_limits","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA Singapore — Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020 (January 2026), clause 4.8 with Tables 4-5 (vitamins and minerals only — no botanical rows)","quote":"4.8 HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5.","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/rehmannia","label":"iHerb Singapore — Rehmannia category page, default listing order","quote":"1 - 1 of 1 result … Dragon Herbs, Rehmannia Six Combination, 100 Vegetarian Capsules","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:29.426925+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}