Fitness YouTuber Greg Doucette has spent years promoting turkesterone, a plant-derived supplement he claimed could produce roid-like muscle gains. The controversy surrounding his Turk Builder supplement spans misleading claims, a dosing scandal, and a return policy that left many customers without real recourse.
Turkesterone is an ecdysteroid, a type of insect hormone found in certain plants like the Ajuga turkestanica plant. Scientists have studied ecdyst*roids since the 1960s to explore their potential anabolic effects, but no credible research demonstrated they worked in humans.
The one study that generated significant hype, the 2019 Eisenman study, used bioelectrical impedance machines to measure muscle mass, a method widely regarded as highly inaccurate. The supplement used in that study also contained only 6 milligrams of ecdysterone instead of the advertised 100 milligrams.
Greg himself dismissed the study’s methodology, calling it “bio electrical impedance analysis, the least accurate method of testing perhaps in the world.”
Despite this, Greg publicly claimed that his Turk Builder supplement caused him to gain 4 lbs of lean contractile tissue in just 30 days. For context, a study administering 600 milligrams of testosterone weekly over 20 weeks resulted in participants gaining an average of 17 lbs of muscle, roughly 3.7 lbs per month. Greg’s plant supplement was supposedly outperforming pharmaceutical testosterone.
In June 2022, Nootropics Depot tested popular turkesterone supplements on the market and revealed that none of them, including Greg’s Turk Builder, actually contained any turkesterone.
Greg’s response shifted the goalposts, suggesting that other ecdyst*roids present in the formula were responsible for the gains, while leaning on the same Eisenman study he had previously dismissed.
He later pivoted to sourcing what he called authentic Ajuga turkestanica from Uzbekistan for Turk Builder 2.0, again claiming eroid-like results. The videos in which he made the original 4 lb muscle gain claims were quietly deleted from his channel.
The return policy attached to Turk Builder was equally problematic. Greg repeatedly advertised a 100% money-back guarantee, but the terms told a different story. The refund applied only to single box purchases.
At the recommended dosage of three capsules per day, one box lasts approximately 13 days, and at least one capsule had to remain inside to qualify. The policy also originally excluded customers outside the United States, not even covering Canada, where Greg is from. A month and a half supply ran around $230 before shipping.
When challenged on the absence of human trials supporting turkesterone, Greg compared it to trenbolone, a synthetic anabolic androgenic st**oid, implying similar uncertainty around both. The comparison drew widespread criticism.
Trenbolone belongs to a class backed by decades of research, while Greg himself had previously acknowledged the science gap, stating, “Turkesterone, not human studies. Turkesterone has not been something that’s been researched by human trials,” before later using that same gap to market his updated product.
