Herbs (Global Traditional) · Traditional Chinese Medicine
Rehmannia glutinosa
Moderate Evidencebotanical
Hermetica Superfood Encyclopedia
Rehmannia glutinosa is a traditional Chinese medicinal herb containing catalpol as its primary bioactive compound, which modulates inflammatory pathways and provides renoprotective effects. Clinical studies demonstrate significant benefits for kidney health and acne reduction through its anti-inflammatory and immune-modulating properties.
Rehmannia glutinosa is a perennial herb in the Orobanchaceae family, native to China, Japan, and Korea, where its tuberous roots are the primary medicinal part used in traditional Chinese medicine (TCM). Extracts are typically prepared from roots (raw or processed/steamed forms like Shu Di Huang) or leaves via solvent extraction or polysaccharide isolation, containing chemical classes including iridoid glycosides (e.g., acteosides), polysaccharides, and phenolic compounds.
Clinical evidence includes a large RCT (n=479) showing Rehmannia glutinosa acteosides (400mg/day) combined with irbesartan improved kidney function in chronic glomerulonephritis patients (PMID: 23519822). A double-blind RCT found leaf extract (100mg/day) reduced acne severity by 21.72% versus 14.20% for placebo after 28 days (PMID: 38651075). A meta-analysis of 17 RCTs (n=1,139) demonstrated benefits for perimenopausal symptoms in breast cancer patients when used as the monarch herb in TCM formulas (PMID: 40628433).
Clinically studied doses include: Root extract standardized to acteosides at 400mg/day (two 200mg capsules twice daily) for kidney conditions; Leaf extract (RGLE) at 100mg/day for acne treatment over 56 days. Traditional TCM preparations vary widely in dosage. Consult a healthcare provider before starting any new supplement.
Rehmannia glutinosa (fresh/dried root) contains minimal macronutrients as a medicinal herb used in small doses. Key bioactive compounds include: Iridoid glycosides (primary actives) — catalpol (0.3–1.5% dry weight, the most studied compound), aucubin, and leonuride; Phenylethanoid glycosides — acteoside (verbascoside) and echinacoside (0.1–0.5% dry weight); Oligosaccharides — stachyose (up to 15% in dried root), raffinose, verbascose, and rehmannioside A–D (collectively 30–40% of dry weight in some preparations); Monosaccharides — glucose and fructose (5–10% dry weight); Amino acids — arginine, glutamic acid, and alanine present in small quantities; Trace minerals — potassium (~800–1,200 mg/100g dried root), calcium (~100–200 mg/100g), magnesium (~50–80 mg/100g), iron (~5–10 mg/100g), zinc (~1–3 mg/100g), and manganese; Vitamins — modest amounts of Vitamin A precursors and Vitamin C in fresh root (degrades significantly upon drying and processing); Polysaccharides — Rehmannia glutinosa polysaccharides (RGPs) comprising 5–15% dry weight, primarily composed of glucose, galactose, and arabinose residues, demonstrated immunomodulatory activity; Sterol compounds — β-sitosterol and stigmasterol in trace amounts (<0.1% dry weight). Processing note: Shu Di Huang (prepared/steamed form) has significantly reduced catalpol content (up to 90% reduction vs. Sheng Di Huang raw form) but increased sugar content and altered glycoside profile, affecting bioavailability and pharmacological action. Catalpol bioavailability in humans is estimated at 20–40% via oral route based on animal pharmacokinetic studies. Fiber content is approximately 2–5% dry weight. Protein content is low, approximately 1–3% dry weight.
Rehmannia glutinosa's primary bioactive compound catalpol inhibits NF-κB signaling pathway, reducing inflammatory cytokine production including TNF-α and IL-1β. The herb's iridoid glycosides enhance renal function by protecting glomerular cells from oxidative stress and modulating immune responses. Catalpol also demonstrates neuroprotective effects by activating CREB signaling and promoting BDNF expression.
A randomized controlled trial with 479 patients showed improved outcomes for chronic glomerulonephritis when Rehmannia glutinosa was combined with conventional therapy, demonstrating strong evidence for kidney health support. A double-blind RCT found leaf extract produced a 21.72% reduction in acne severity scores after 28 days of treatment. While these studies show promising results, most clinical evidence comes from combination formulas rather than isolated Rehmannia glutinosa. Additional large-scale trials are needed to establish optimal dosing protocols for individual conditions.
Rehmannia glutinosa is generally well-tolerated with mild gastrointestinal upset reported in some users. The herb may interact with diabetes medications by affecting blood glucose levels and should be monitored in diabetic patients. Pregnancy and breastfeeding safety has not been established through clinical trials, so use should be avoided during these periods. Individuals with digestive weakness or diarrhea should use caution as the herb's cooling nature may worsen these conditions.
