'Turkesterone' is the word on everyone's lips at the moment, the almost too-good-to-be-true plant steroid that works directly in muscle to promote protein synthesis and growth without affecting androgen levels. But how does it work, and more importantly, why is it legal?
Turkesterone is what is known as a secondary metabolite, a compound produced by plants which, rather than performing some internal function, exists to manipulate their external environment. Secondary metabolites can be used to repel herbivores, attract pollinators or carnivorous bugs (to eat those pesky herbivores), or affect the growth of neighboring plants. Turkesterone itself is a type of phytoecdysteroid, a mimic of insect moulting hormones which, when consumed by herbivorous insects, negatively affects their moulting cycle and makes them quite ill. In this manner, phytoecdysteroids are capable of reducing herbivory and protecting the plant from its attackers, making them beneficial for the plant to produce.
Now, humans don't shed our outer shell like insects do during their moulting cycle, so what's all this got to do with us?
Sterols are compounds which are quite ubiquitous amongst plant and animal cells as they are used to maintain the stability of cell membranes, and many organisms have adapted derivatives of these structure-providing compounds as hormones. Where insects use the sterol derivative 20-hydroxyecdysone (ecdysterone) to control moulting, humans analogously use sterol derivatives such as testosterone and estrogen to control the growth and maintenance of various tissues. Structurally, these compounds all share the same chemical backbone, and as such it follows that compounds such as ecdysterone and turkesterone produced by plants to mess with their insect foes may also have coincidental and unintended effects in humans.
To get to why turkesterone and ecdysterone are of such interest, we have to talk about estrogen. An important and somewhat little known fact about estrogen is its anabolic activity in muscle, via beta estrogen receptors. Estrogen helps maintain healthy muscle mass in women and men, and loss of estrogen signalling in post-menopausal women is postulated to be a major cause of frailty. Ecdysterone and turkesterone, among other related compounds, bind relatively selectively to beta estrogen receptors in muscle and encourage muscular hypertrophy via this route. With very little activity at alpha estrogen receptors or androgen receptors, these ecdysteroids manage to have minimal reproductive hormonal effects, as compared with traditional anabolic steroids such as exogenously administered testosterone which homeostatically reduces the body's natural testosterone levels (known as 'shutdown'). The activities of ecdysterone and turkesterone in muscle have been compared with the anabolic steroid methandrostenolone (dianabol), and while devoid of its androgenic effects (and shutdown), have comparable effects on muscle growth and endurance specifically. Some research has even demonstrated greater anabolic activity of ecdysteroids over dianabol, dienedione (pro-nandrolone) and even some some SARMS (Selective Androgen Receptor Modulators), to an extent comparable to IGF-1 and dihydrotestosterone. Turkesterone possesses about 22% greater activity than ecdysterone due to a slight structural difference (11 alpha hydroxylation) conferring greater potency, although whether this difference can be rectified with simple adjustments of dose is yet to be determined.
So, the big question is why ecdysteroids like turkesterone and ecdysterone are legal at all, if SARMS and anabolic androgenic steroids aren't? The answer comes down to certain intricacies of how the Standard for the Uniform Scheduling of Medicines and Poisons (aka the Poisons Standard) works. The Poisons Standard is a legislative instrument constructed and administered by the TGA which exists to control how medicines and poisons are regulated, who is allowed to sell them and for which conditions. To be considered for inclusion into the Standard (and thus restricted from sale for regular consumption), a compound usually must be more than simply biologically active (as all compounds are biologically active). The compound must be, at least to some degree, potentially dangerous. For synthetic compounds, the process of scheduling (and hence restriction) is relatively straightforward. The compound does not exist in nature, and as such no one could likely be expected to stumble across it in day-to-day life. Anyone in possession of such a compound would be found to be in breach of the legislation as there is no way they could have obtained such a compound innocently. This is the case with classical SARMS and androgenic anabolic steroids, which are largely synthetic and can cause negative effects on the androgen system, so warrant being scheduled. But what if the compound is found in food?
In such a case, there has to be a strong reason for scheduling, as the compound is likely to be unwittingly trafficked by food producers and consumed by the general public. The compound would have to be particularly dangerous to human health to warrant something so complex as the restriction or banning of a common food substance outright. The extent of commercial disruption would be wholly unjustifiable if the compound was devoid of toxicity, possessing only non-deleterious biological effects such as moderate muscle hypertrophy, as is the case of ecdysteroids.
Ecdysterone and turkesterone aren't toxic at all, and are found at up to 0.08% concentrations in Popeye's favourite food: raw fresh spinach. When you dry spinach to remove its 93% water content, you're left with a raw herb with 1.14% ecdysteroids. For a minumum active dose of about 100mg of ecdysterone and turkesterone (and relatives), only about 9 grams of dried spinach would need to be consumed. Given the safety profile of ecdysteroids and spinach's long track record of consumption as a safe and edible food substance, scheduling of ecdysteroids would be difficult at best.
The only remaining concern is WADA, the World Anti-Doping Agency. WADA exist to make some attempt at preventing athletes in sports from gaining any sort of unnatural advantage over their competitors, and are somewhat more promiscuous in their selection of compounds to prohibit in sport. If ecdysteroids were only found in plants which were not classically viewed as foodstuffs, they would most likely be banned by WADA as, despite being safe, they meet the exclusion criteria of being performance enhancing substances. However, due to their presence at exceedingly high concentrations in foodstuffs such as spinach, where an athlete could easily ingest performance-enhancing quantities of the substances via a diet rich in quiche, a ban of ecdysteroids would be unjustifiable and extremely difficult to enforce. What's more is that some research suggests that all plants have the capacity to produce active ecdysteroids under the right growth conditions, after screening hundreds of species of plants and finding at least some ecdysteroids in most of them, with some species showing significant plant-to-plant differences in concentrations of ecdysteroids simply due to individual variations. This of course makes sense; all plants contain the cell-membrane stabilising sterols previously mentioned, and so it is fair to assume that all plants have the capacity to slightly modify these into ecdysteroids. Some plants have unusually high concentrations of ecdysteroids, such as those used in our products, but the fact that all plants could contain at least some means that everyone is intaking ecdysteroids naturally in their diet every day.
Compare this with whey protein. Whey protein is an extract of milk, containing high levels of the essential amino acid leucine. Leucine is an anabolic amino acid which encourages muscle protein synthesis via the mTOR pathway, and so is unquestionably performance enhancing, aside from simply being a necessary amino acid to consume regularly in the diet. Just as eating a diet high in leucine-rich protein such as whey is considered to be a fair and natural form of performance-enhancement, so too should be the consumption of ecdysteroid extracts, being naturally present in many if not most food plants. Taking supplements rich in ecdysteroids like ecdysterone and turkesterone is as such not fundamentally more 'unfair' than consuming something as innocuous as protein powder, and is one of the most powerful tools that everyone looking to maximise the outcomes of their training should have in their arsenal.