Turkesterone

Turkesterone is an ecdysteroid — a steroid made by plants and insects, not a peptide and not a SARM (selective androgen receptor modulator, a class of muscle-building drugs). It is sold as a dietary supplement and pitched as a “natural anabolic” alternative to steroids. The honest picture? On its own, turkesterone has almost no solid human evidence behind its muscle and strength claims. The little supportive science that exists is mostly about a chemical cousin called 20-hydroxyecdysone — and even that research is shaky and inconsistent.

What it is

Turkesterone is an ecdysteroid (phytoecdysteroid) — that is, a steroid produced by plants and insects, carrying many hydroxyl groups (small chemical units of oxygen and hydrogen). Chemically, it is a close relative of 20-hydroxyecdysone (also called 20E or “ecdysterone”), differing by just one extra hydroxyl group. It is not a peptide and not a SARM. The material sold in supplements is mostly extracted from a plant called Ajuga turkestanica and a few related plants.

The proposed way it works comes mostly from lab-dish and animal studies on ecdysteroids in general — not from turkesterone itself. One important point: ecdysteroids do not plug into the human androgen receptor (the docking point that classic anabolic steroids use). Instead, the suggested routes involve estrogen receptor beta (ERβ) signaling and a downstream pathway called PI3K/Akt that helps build proteins. But these are still just ideas. How turkesterone actually works in people is not established.

The claims

Sellers and users describe turkesterone as a “natural anabolic” for building muscle, gaining strength, and recovering faster — supposedly delivering quicker lean-muscle gains with none of the usual downsides: no androgenic side effects, no drop in your own testosterone, and no need for post-cycle therapy (the recovery regimen people use after steroid cycles). It gets sold as a “legal, natural alternative to anabolic steroids and SARMs.”

These claims are largely unsupported by direct human evidence on turkesterone.

What the evidence actually shows

• Turkesterone specifically: essentially no rigorous human evidence. There are no large, peer-reviewed, placebo-controlled human trials (studies where some people get the real thing and others get a dummy, with neither group knowing which) showing that turkesterone builds muscle or strength. A 2024 review in Nutrients points out that human data on turkesterone as an isolated compound is minimal to nonexistent, and that the body-composition and strength claims lean on guesses borrowed from 20-hydroxyecdysone and from animal research.
• 20-hydroxyecdysone (the related, better-studied compound):
  • Isenmann et al. (2019, Archives of Toxicology) ran a 10-week resistance-training trial (about 46 young men) using an ecdysterone-containing supplement. They reported noticeably bigger gains in muscle mass and one-rep-max bench press, with no rise in markers of liver or kidney damage. This is the single most-cited human study supporting an anabolic effect. But note: the group was small, and lab testing has found that the actual ecdysterone in marketed products can differ a lot from what the label says, which makes the real dose hard to pin down.
  • Parr et al. (2015, Biology of Sport, “Ecdysteroids: A novel class of anabolic agents?”) is a review that lays out the anabolic idea, including the possible ERβ activity, while flagging big limitations: how potent these compounds really are, how much actually gets absorbed, and how the body breaks them down.
  • Preclinical/animal: rodent studies report a boost in protein synthesis, often without messing up hormones, plus ERβ activity in lab-grown muscle cells (C2C12 myotubes). None of this proves it works in humans.

Bottom line on evidence: the science for ecdysteroids as a class is weak and inconsistent, and the evidence for turkesterone itself in humans is effectively absent. On top of that, how much of an oral dose actually gets absorbed in mammals is generally thought to be low — a caveat that comes up again and again in the research.

Legal and regulatory status

• FDA: Turkesterone is not an FDA-approved drug. Ecdysteroids are sold as dietary-supplement ingredients. There is no known FDA enforcement action specifically calling turkesterone or ecdysterone an unlawful dietary ingredient. (By contrast, the FDA has publicly said that SARMs are not lawful dietary-supplement ingredients — but SARMs are a different class of drug with different chemistry.)
• DEA: Ecdysteroids are not controlled substances and are not anabolic steroids under the Anabolic Steroid Control Act, which covers testosterone-based androgens — again, a different group of compounds. No DEA scheduling of turkesterone is known.
• Anti-doping (WADA): Ecdysterone (20-hydroxyecdysone) is not on the WADA Prohibited List. It has been on the WADA Monitoring Program since 2020 and remains on the 2026 Monitoring Program — and monitored substances are not prohibited. Turkesterone is not separately listed as banned. (By contrast, SARMs fall under S1.2 anabolic agents, and GW-501516/SR9009 under S4.5 — those are genuinely banned, but unrelated to turkesterone.)

The main real-world regulatory headache is label accuracy: independent lab analyses have repeatedly found ecdysteroid products mislabeled for how much they contain and how pure they are.

Safety

There is no reliable human safety dataset for turkesterone. Its long-term safety in people is unknown and unstudied. The animal data and short-term human data we do have on ecdysteroids generally don’t show androgenic effects, testosterone suppression, or obvious toxicity — but that’s only reassuring for short-term use, and mostly for 20E, not a clean bill of health for turkesterone.

The clearest documented hazards are about product quality, not the molecule itself: mislabeling, underdosing, and possible adulteration or contamination of supplements. Some case reports describe liver damage tied to “turkesterone” products, but those likely reflect adulterants or other ingredients rather than turkesterone itself — and the link is unproven.

It’s worth being clear: the scary harms linked to other compounds do not belong to turkesterone. Testosterone suppression, lowered HDL (“good” cholesterol), and raised liver enzymes are documented with SARMs; vision and light-perception problems with andarine (S-4); and GW-501516 (cardarine) development was stopped after rodent studies showed it caused cancer (tumors in multiple organs). None of these are established turkesterone effects.

Bottom line

Turkesterone is an ecdysteroid with a catchy “natural anabolic” marketing story but little-to-no direct human evidence behind its muscle and strength claims. The supporting science is mostly about the related compound 20-hydroxyecdysone, and that research is itself weak and mixed. Turkesterone is not FDA-approved, not DEA-controlled, not an anabolic steroid under US law, and not WADA-prohibited (ecdysterone is merely monitored). The clearest documented risk is supplement quality and mislabeling, and long-term human safety is unknown.

Evidence grade: 1/10 · Unsupported.

Sources

• Parr MK et al. “Ecdysteroids: A novel class of anabolic agents?” Biology of Sport 2015;32(2):169–173 (PMID 26060342)
• Isenmann E et al. “Ecdysteroids as non-conventional anabolic agent: performance enhancement by ecdysterone supplementation in humans.” Archives of Toxicology 2019;93(7):1807–1816
• Todorova V et al. “Ecdysterone and Turkesterone—Compounds with Prominent Potential in Sport and Healthy Nutrition.” Nutrients 2024 (PMC11085066)
• WADA 2026 Monitoring Program
• WADA: “WADA’s 2026 Prohibited List now in force”
• FDA: New Dietary Ingredient (NDI) Notification Process