Ecdysterone
Summary
Ecdysterone is a plant steroid marketed for muscle gain. Two small training trials found larger strength or muscle gains, while an 8-week trial in trained men, a 12-week trial of a mislabelled product and an acute turkesterone study found no effect. Lab tests show many products hold far less than labelled. WADA monitors ecdysterone in sport but does not prohibit it.
Key facts
- On WADA's 2027 Monitoring Program under anabolic agents, in and out of competition. Monitored substances are tracked for misuse patterns but are not prohibited. The team behind the main positive trial has argued for listing it under S1.2 'other anabolic agents'.[11][1][9]
- A lab analysis of 12 ecdysterone supplements found actual content generally far below the label; only 3 of the 12 were within 50% of the stated amount. The product used in a 2025 trial held less than 1% of its labelled 20E.[8][2]
- A handful of small supplement trials (11–46 people each, up to 12 weeks) with mixed results, and no meta-analysis. A larger trial of a purified 20E drug candidate is covered separately below.[1][2][3][4][5][12]
- Turkesterone is a related ecdysteroid from Ajuga turkestanica. The only human study found was an 11-person acute crossover that showed no significant effect on IGF-1 or resting metabolic rate.[10][5]
- A purified 20E drug candidate (BIO101) given at 175 or 350 mg twice daily to 233 older adults with sarcopenia did not significantly improve walking speed in the main analysis.[7]
- 7 graded human outcomes on this page
- October 13, 2026
How it works
ProposedRat and cell studies suggest ecdysterone acts through estrogen receptor beta rather than the androgen receptor; in rats it enlarged muscle fibres more than metandienone and other anabolic agents given at the same dose (animal data). The developer of a purified 20E drug describes it as an activator of the MAS receptor. In people it is cleared quickly, with a mean half-life of 2.4–4.9 hours.[9][7][6]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Muscle function in older adults | Grade D | Mixed | RCT · n = 233 · 2025 | 1 row |
| Strength and muscle | Grade D | Improved | RCT · n = 46 · 2019 | 4 rows |
| Body composition | Grade D | Mixed | RCT · n = 20 · 2025 | 1 row |
| Turkesterone | No effect | No effect | Crossover RCT · n = 11 · 2024 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Walking speed in older adults with sarcopenia (purified 20E drug candidate) | Mixed | Grade D | RCT · n = 233 · 2025 Community-dwelling adults aged 65+ with sarcopenia at risk of mobility disability Form: BIO101 (purified 20E, at least 97%; investigational drug) · Dose: 175 mg or 350 mg twice daily · Duration: 6–9 months 400-metre walk speed improved by 0.07 m/s vs placebo with 350 mg twice daily in the full analysis (not significant) and by 0.09 m/s in the per-protocol analysis (P = 0.008). | 40026058 (opens PubMed)Source [7] |
| Muscle mass and bench press strength during resistance training | Improved | Grade D | RCT · n = 46 · 2019 Young men in a 10-week strength-training programme (Germany) Form: Ecdysterone capsules (6 mg 20E plus 100 mg leucine per capsule) · Dose: 12 mg or 48 mg 20E/day · Duration: 10 weeks Participants dosed with ecdysterone gained more muscle mass and more one-repetition bench press strength than comparison participants; liver and kidney markers did not rise. | 31123801 (opens PubMed)Source [1] |
| Muscle strength with moderate training in adults over 50 | Improved | Grade D | RCT · n = 45 · 2021 Adults over 50 in a 12-week moderate-intensity training programme (Spain); 23 extract and 22 placebo analysed Form: Spinach (Spinacia oleracea) extract · Dose: 2 g/day of extract (4 × 500 mg capsules) · Duration: 12 weeks Strength improved in both groups, but isokinetic and isometric knee-extension gains were larger with the extract; no adverse events were recorded. | 34959924 (opens PubMed)Source [3] |
| Body fat and fat burning during resistance training | Mixed | Grade D | RCT · n = 20 · 2025 Healthy young men in supervised resistance training; 10 per group Form: Asparagus-derived 20E · Dose: 30 mg 20E/day · Duration: 12 weeks Arm, leg and abdominal fat fell within the 20E group, but only arm fat fell more than with placebo. Fat oxidation differed between groups only at 40% of peak oxygen uptake, and insulin and insulin-sensitivity changes were reported within the 20E group only. | 41485968 (opens PubMed)Source [4] |
| Strength, body composition and hormones during resistance training | No effect | No effect | RCT · n = 45 · 2006 Resistance-trained young men (USA); 45 across four groups (placebo, ecdysterone and two other supplements) Form: Ecdysterone (20-hydroxyecdysone) supplement · Dose: 200 mg/day as labelled · Duration: 8 weeks No differences from placebo in fat-free mass, body fat, bench press or leg press strength, sprint power, testosterone or cortisol. | 18500969 (opens PubMed)Source [12] |
| Strength and muscle with a commercial 20E plus diosgenin product | No effect | No effect | RCT · n = 24 · 2025 Resistance-trained young men (Germany); 28 randomised, 24 completed Form: Commercial 20E plus diosgenin capsules (labelled 25 mg 20E per capsule) · Dose: 3 capsules/day as labelled · Duration: 12 weeks Squat and bench press strength, muscle mass and muscle thickness rose in both groups with no difference between product and placebo. Lab analysis found less than 1% of the labelled 20E and 10.4% of the labelled diosgenin, and the capsules showed no muscle-cell activity. | 40781783 (opens PubMed)Source [2] |
| IGF-1 and resting metabolic rate after single turkesterone doses | No effect | No effect | Crossover RCT · n = 11 · 2024 Healthy young men Form: Turkesterone · Dose: Single doses of 1,000 mg and 2,000 mg vs placebo · Duration: Acute (measured up to 24 hours) No significant effect on serum IGF-1, resting metabolic rate, or lipid and carbohydrate metabolism; heart rate, blood pressure and digestion were unaffected. | 40757520 (opens PubMed)Source [5] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| 20-hydroxyecdysone (spinach, asparagus or other plant extracts) | Varies[6] | Purified 20E reached blood exposures that rose less than proportionally with dose (100–1,400 mg) and was cleared with a mean half-life of 2.4–4.9 hours; exposure was slightly lower in older adults.[6] | Phase 1 doses up to 1,400 mg once and 450 mg twice daily for 14 days caused only mild to moderate adverse events. Training trials at about 3–48 mg/day reported no liver or kidney marker rise or no adverse events.[6][1][3] | Strength and muscle in training adults, body fat, and sarcopenia (as a drug candidate) |
| Turkesterone (Ajuga turkestanica extracts) | Varies[5] | The single human study measured hormones and metabolism for 24 hours but not blood levels of turkesterone.[5] | Single 1,000 mg and 2,000 mg doses did not change heart rate or blood pressure and caused no digestive complaints in 11 men.[5] | Acute IGF-1 and metabolic rate (one 11-person study) |
Studied doses
Doses studied in human trials ranged from about 3.2 mg/day of 20E (from 2 g of spinach extract, 12 weeks) 12–48 mg/day (10 weeks) and a labelled 200 mg/day (8 weeks, content not verified) up to 350–700 mg/day of a purified 20E drug candidate in older adults (6–9 months). Turkesterone has only been given as single 1,000 mg and 2,000 mg doses. Actual product content often differs widely from the label.[3][2][1][12][7][5][8]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Athletes in tested sport
- WADA monitors ecdysterone in and out of competition, although it is not prohibited, and independent testing shows products often do not match their labels.[11][8]
- Pregnancy, breastfeeding, children and teens
- No safety data: every human study found enrolled adults only.[1][3][6][7]
- Hormone-sensitive conditions
- Animal and cell work points to an estrogen receptor beta pathway; effects in people with hormone-sensitive conditions have not been studied.[9]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
- Extract weight is not 20E contentLabels may list grams of plant extract rather than 20E: 2 g/day of the spinach extract used in one trial supplied only about 3.2 mg of 20E.[3][2]
- Expect a gap from the labelIndependent analysis found most of 12 ecdysterone products well below their labelled 20E, and a 2025 trial product held under 1% of it.[8][2]
Frequently asked questions
Does ecdysterone build muscle?
The evidence is thin and mixed. A 10-week trial in 46 young men and a 12-week trial in adults over 50 found larger strength or muscle gains with 20E, but an 8-week trial in 45 trained men and a 12-week trial of a commercial product (which held under 1% of its labelled 20E) found no difference from placebo. No meta-analysis exists.[1][3][12][2]
Is ecdysterone banned in sport?
Not on the 2027 list. WADA places it on its Monitoring Program for anabolic agents, in and out of competition, which tracks use without prohibiting it. Researchers behind the main positive trial argued for listing it under S1.2 'other anabolic agents'.[11][1]
Is turkesterone the same as ecdysterone?
No. Both are ecdysteroids, but turkesterone comes mainly from Ajuga turkestanica. Its only human study, in 11 men given single 1,000 mg and 2,000 mg doses, found no significant effect on IGF-1 or resting metabolic rate.[10][5]
Sources
- [1]Ecdysteroids as non-conventional anabolic agent: performance enhancement by ecdysterone supplementation in humans.. Arch Toxicol, 2019. RCT
- [2]How reliable is the labeling of a commercial phytosteroid product? A 12-week randomized double-blind training study.. J Int Soc Sports Nutr, 2025. RCT
- [3]A 12-Week Randomized Double-Blind Placebo-Controlled Clinical Trial, Evaluating the Effect of Supplementation with a Spinach Extract on Skeletal Muscle Fitness in Adults Older Than 50 Years of Age.. Nutrients, 2021. RCT
- [4]Effects of Asparagus-Derived 20-Hydroxyecdysone Supplementation on Fat Oxidation and Insulin Sensitivity in Resistance-Trained Males.. J Nutr Sci Vitaminol (Tokyo), 2025. RCT
- [5]The Effects of Multiple Acute Turkesterone Doses on Indirect Measures of Hypertrophy and Metabolic Measures: A Preliminary Investigation.. Muscles, 2024. crossover-RCT
- [6]A Phase 1 study for safety and pharmacokinetics of BIO101 (20-hydroxyecdysone) in healthy young and older adults.. J Cachexia Sarcopenia Muscle, 2023. PK-study
- [7]BIO101 in Sarcopenic Seniors at Risk of Mobility Disability: Results of a Double-Blind Randomised Interventional Phase 2b Trial.. J Cachexia Sarcopenia Muscle, 2025. RCT
- [8]How reliable is dietary supplement labelling?-Experiences from the analysis of ecdysterone supplements.. J Pharm Biomed Anal, 2020. observational
- [9]Ecdysteroids: A novel class of anabolic agents?. Biol Sport, 2015. animal-study
- [10]Ecdysterone and Turkesterone-Compounds with Prominent Potential in Sport and Healthy Nutrition.. Nutrients, 2024. review
- [11]The 2027 Monitoring Program. World Anti-Doping Agency, 2026. guideline
- [12]Effects of methoxyisoflavone, ecdysterone, and sulfo-polysaccharide supplementation on training adaptations in resistance-trained males.. J Int Soc Sports Nutr, 2006. RCT
What changed
- Initial editorial evidence review: every PMID checked against NCBI esummary (title, year, no retraction or expression-of-concern flag); doses, sample sizes and durations re-read against the PubMed abstract or open full text; grades kept conservative; interactions limited to what a cited source supports.
- Adversarial review: added the null 8-week Wilborn 2006 trial (PMID 18500969) for balance, limited the 'small trials' key fact to supplement trials (the 233-person drug trial is separate), and noted the spinach-extract authors' nitrate caveat.