What is your thought on this for a fatloss supplement?
Well, this depends on what your expectations are with it's use. The fact that guggulsterones are sterols, they will impart action on both cholesterol (positive) and other steroids (testosterone, estrogen, progesterone). But - and maybe most importantly; there was a concern posed some time ago about the potential for guggulsterones to impart agonistic action on ER-alpha and PR (even going as far as saying the progesterone effect is what people feel when they get "warm" etc... after taking guggulsterones); while offering an antagonistic effect at the level of the androgen receptor. Looks pretty bad; but like many plants - especially those unstandardized extracts, you take the good with the bad (perhaps this is "another" green tea with increases in SHBG - I don't mean that it inherently increases SHBG, but by design can you look at one action and dismiss the rest?).
There are obvious effects that would be very positive in terms of pro-thyroid events with stimulation of metabolism; but is that even good in terms of the potential for muscle catabolism? Possibly if controlled catabolism is what we're talking about...because as most love to forget...FAT LOSS is a catabolic process and running "low" during some time frames of the day can actually be a VERY good thing (although I think people who do long-period fasts are crazy to sacrifice so much positive nitrogen balance; they KINDA get this point but take it to a serious EXTREME and are likely sacrificing maximum muscle protein synthesis).
Increased thyroid levels may also increase mitochondrial uncoupling of muscle tissue and decrease insulin secretion and nitric oxide production. Although fat loss will still be the primary effect, a portion of the weight lost may be from muscle. Fortunately, you can avoid or at least highly limit the amount of catabolism caused by increased thyroid levels by increasing your testosterone levels, because testosterone blocks the pathway through which thyroid-induced protein uncoupling occurs.
So - do I have people use them? NO!
Is that because I think this effect at the level of the ER-alpha/PR/AR is significant? ABSOLUTELY NOT! We know the affinity isn't good at all, especially ER-alpha. The thing is outside of lipids (cholesterol); I don't think they produced significant weight loss effects in the history of their use; so why even make it an issue. Plus there are so many SUPERIOR ingredients out there that would work infinitely better in terms of fat loss.
Do I think you need to avoid them like the plague; like say soy? NO!
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