Side Effects of Turkesterone: What We Know
Turkesterone became a social-media sensation as a supposed "natural anabolic" that builds muscle without the downsides of steroids. Our editorial team looked past the marketing to examine what turkesterone actually is, what is known about its side effects, and why the biggest safety questions are about product quality and missing human data rather than dramatic toxicity.
What turkesterone is
Turkesterone is an ecdysteroid, a class of steroid-like compounds found in certain plants and insects. In insects, ecdysteroids regulate molting; in plants such as Ajuga turkestanica, from which turkesterone is extracted, they are thought to play a defensive role. Despite the "steroid" in the name, ecdysteroids are structurally different from human anabolic-androgenic steroids.
The marketing claim is that turkesterone increases muscle protein synthesis without binding to the androgen receptor, so it would not cause the hormonal side effects of anabolic steroids. This is why it is sold as a dietary supplement rather than classed as a controlled substance.
Importantly, most of the supporting research involves cell cultures, insects or rodents. Rigorous, well-controlled human trials specifically on turkesterone are very limited, which means the side-effect profile in people is not well characterized.
In the US, turkesterone is sold over the counter as a dietary supplement. It is not approved as a drug, and the FDA does not evaluate supplements for effectiveness before sale, so claims on labels are not independently verified.
Reported and plausible side effects
Because solid human safety data are scarce, most information about turkesterone side effects comes from user reports and from what is known about ecdysteroids generally. The most commonly described issues are digestive: nausea, stomach discomfort and loose stools, particularly at higher doses or on an empty stomach.
Some users report lethargy, headaches or appetite changes, but these reports are anecdotal and not confirmed in controlled studies. Without placebo comparison, it is impossible to know how much of this is due to the supplement itself.
Ecdysteroids are generally considered to have low acute toxicity in animal studies, which is often cited as reassuring. However, low acute toxicity in animals does not establish long-term safety in humans, especially for continuous use over months.
There is no evidence that turkesterone causes the classic anabolic-steroid side effects such as testosterone suppression, acne or hair loss, and it is not known to aromatize to estrogen. This absence of androgenic effects is also part of why its muscle-building claims remain scientifically uncertain.
The real safety issue: product quality
For turkesterone, the most pressing safety concern is not the molecule itself but what is actually in the bottle. Independent testing of ecdysteroid supplements has repeatedly found that the stated ecdysteroid content often does not match the label.
A 2022 analysis of ecdysteroid supplements on the market found wide variation, with some products containing little of the claimed compound and others including undisclosed ingredients. In the US dietary-supplement framework, this kind of mislabeling is a known risk across many categories.
Adulteration is a related worry. Because supplements are not pre-approved, a product marketed as "natural" could in principle be spiked with other substances. Third-party testing programs such as NSF Certified for Sport or Informed Sport reduce this risk and are strongly advisable for competitive athletes.
This matters because a side effect attributed to turkesterone might actually come from a contaminant or from a different compound entirely. When the product is poorly characterized, so is its safety.
| Concern | What it means | How to reduce risk |
|---|---|---|
| Label accuracy | Actual ecdysteroid content may differ | Choose third-party-tested brands |
| Adulteration | Undisclosed ingredients possible | Avoid unverified sellers |
| Unknown long-term effects | No human chronic-use data | Use caution; discuss with a doctor |
| Drug interactions | Poorly studied | Review with a pharmacist |
Who should be especially cautious
Certain groups should be particularly careful or avoid turkesterone altogether. Pregnant and breastfeeding women should not use it, because there is no safety data for these situations, which is the standard precaution for unstudied supplements.
People with existing liver or kidney conditions should consult a physician first. Although turkesterone is not known to be hepatotoxic, the broader supplement market has a documented history of liver injury linked to contaminated or mislabeled products, so caution is warranted.
Anyone taking prescription medications should check for possible interactions with a pharmacist, because ecdysteroid interactions are poorly studied and cannot be assumed to be absent.
Competitive athletes should confirm their sport's rules. Turkesterone itself is not on the WADA Prohibited List, but contamination with banned substances is a genuine risk with unverified supplements, and the athlete bears responsibility for a positive test.
- Pregnant or breastfeeding individuals — avoid due to lack of data.
- People with liver or kidney disease — consult a physician first.
- Anyone on prescription medication — review interactions with a pharmacist.
- Drug-tested athletes — use only third-party-tested products, if at all.
Putting the risks in perspective
Turkesterone is not an anabolic steroid and does not appear to carry the hormonal harms associated with that class. At the same time, the evidence that it builds meaningful muscle in humans is weak, so the risk-benefit balance rests on uncertain benefits against incompletely known risks.
The most reasonable interpretation of the current evidence is that turkesterone is probably low-risk for short-term use in healthy adults, with digestive upset the most likely complaint, but that long-term safety is simply unestablished.
Because the supplement market is uneven, any decision to try turkesterone should include choosing a reputable, tested brand and treating it as an experiment with modest expectations rather than a proven tool.
Honest uncertainty is the key message: absence of reported harm is not the same as proof of safety, and marketing enthusiasm should not be mistaken for evidence.
Our Editorial Conclusions
The known side effects of turkesterone are mostly mild and digestive, and it lacks the androgenic harms of anabolic steroids. The larger safety issues are the lack of human long-term data and the poor reliability of supplement labels.
If you choose to use it, prioritize third-party-tested products, start conservatively, and stop if you notice adverse effects. Pregnant women, people with organ disease and those on medications should be especially cautious or avoid it.
Remember that a supplement with uncertain benefits does not need to carry even small risks if it is unlikely to help you reach your goals faster than training and nutrition will.
For related reading, our editors suggest articles on how to evaluate supplement quality and third-party certifications, on creatine as an evidence-based muscle aid, and on tribulus and other "natural testosterone" claims.
References
- Isenmann E, Ambrosio G, Joseph JF, et al. Ecdysteroids as non-conventional anabolic agent: performance enhancement by ecdysterone supplementation in humans. Arch Toxicol. 2019;93(7):1807–1816.
- Dinan L, Dioh W, Veillet S, Lafont R. 20-Hydroxyecdysone, from plant extracts to clinical use: therapeutic potential for the treatment of neuromuscular, cardio-metabolic and respiratory diseases. Biomedicines. 2021;9(5):492.
- Ambrosio G, Joseph JF, Wuest B, et al. Detection and quantification of ecdysterone in dietary supplements. Drug Test Anal. 2022;14(5):803–814.
- Geldof L, Deventer K, Van Eenoo P. Ecdysteroids and sports: a review. Steroids. 2017;123:1–10.
- Navarro VJ, Khan I, Björnsson E, et al. Liver injury from herbal and dietary supplements. Hepatology. 2017;65(1):363–373.
- US Food and Drug Administration. Dietary supplements. FDA Consumer Information; 2023.
