Should You PCT After SARM Only Cycle?

Conclusion: No. A SERM (what is used in PCT) increases FSH (as well as LH), which will help users recover from a low testosterone state given SARMs lower FSH. However the 2013 study on LGD (a good proxy for SARMs in general) showed that subjects returned to baseline 35 days after discontinuing the compound. Therefore, my recommendation is to avoid PCT unless low T symptoms persist beyond 4-5 weeks after discontinuing SARM.

SARMs are not steroids, and will not convert into estrogen. Accordingly, an AI is not required.

Credit goes to u/MezDez for the research topic and helping lead the way in helping the sub understand the place PCT occupies in a SARM only cycle.

Firstly, what is a SERM? SERM stands for selective estrogen receptor modulator and has an impact on estradiol levels.

Compounds that modulate estradiol levels in these clinical conditions are referred to as selective estrogen receptor modulators (SERMs)... In a certain subset of infertile men, particularly those with hypogonadism, or those who have a low serum testosterone to estradiol ratio, there is some evidence suggesting that SERMs... can reverse the low serum testosterone levels or the testosterone to estradiol imbalance and occasionally improve any associated infertile or subfertile state.

A SERMs role is to increase luteinizing hormone (LH) and follicle-stimulating hormone (FSH) that will increase testosterone when coming from a suppressed state:

(SERMs) work as estrogen antagonists at the level of the pituitary gland and thus stimulate the release of luteinizing hormone and follicle-stimulating hormone, which in turn drive both the steroidogenic and spermatogenic functions of the testes.

SARMs do not lower LH like steroids - instead individuals will experience suppression of testosterone by lowering FSH. The take away therefore is that SARMs may not impact testosterone as much as AAS which act against both LH and FSH, but will still suppress an individual:

Serum luteinizing hormone levels did not show any meaningful changes from baseline, whereas the follicle-stimulating hormone levels were suppressed... Upon discontinuation of LGD-4033, the hormone levels returned to baseline by day 56.

The return to baseline is important. Free test, SHBG, LH, and FSH all returned to baseline, regardless of dose (0.1mg, 0.3mg and 1mg respectively).

How long does it take for SERMs to kick in? Too long, perhaps:

After initiation of therapy, steady state concentrations for tamoxifen are achieved in about 4 weeks and steady state concentrations for N-desmethyl tamoxifen are achieved in about 8 weeks, suggesting a half-life of approximately 14 days for this metabolite.

All that said, the incidence of low T post cycle and the impatience of research subjects in returning their T levels to within a normal range turn many within r/PEDs to PCT. While I don't believe PCT is necessary based on the data I've reviewed here, perhaps there are other factors in play that I'm not considering where PCT would be beneficial. And/or, SARMs are an emerging product and it's very possible we don't know everything just yet and positions on this topic may evolve. Ultimately, you're responsible for your own health, risks and decisions and should plan accordingly. Please also factor the incidence, however small, of adulterated product such as Winstrol/oral AAS and prohormones being sold as SARMs.