What are the side effects of S-23?

Users most often report suppression, acne, hair loss, aggression, night sweats. Side effects came up 31 times across 83 reports.

S-23 is not an approved supplement and carries serious risks. User reports can't establish safety. PubMed lists 6 meta-analyses and 26 randomized trials. Talk to a doctor or pharmacist, especially if you take other medication.

S-23 side effects

Across 83 first-hand reports, people mentioned a side effect 31 times (about 37 per 100 reports). The most common: suppression, acne, hair loss. User reports show what people notice — they can't tell you whether S-23 is safe for you.

High-risk compound. Not an approved supplement; serious and sometimes irreversible risks, banned in sport, may be restricted where you live.

Reported side effects

suppression19

acne3

hair loss3

aggression2

night sweats2

fatigue2

What got worse for some people

Hormones100% worse · 0% better · of 6

In their own words

“It personally was my favorite cycle. The strength and size gains were better than RAD.”

HelpedRead the discussion ↗

“S-23 is very strong but the side effects suck ass for a ton of people, some can use it fine but for others (like me) it has like tren level sides and simply isn't worth it.”

MixedRead the discussion ↗

“Really strong, be sure to have test base. Really acnee prone sarm. It felt like tren for me.”

MixedRead the discussion ↗

“I get amazing results from rad140 and almost none from s23 which is supposed to be one of the strongest.”

Didn't helpRead the discussion ↗

“I'm almost convinced that they're underdosed or just garbage...I just started TRT 4months ago on 150mg/week and my body composition has changed from that alone”

Didn't helpRead the discussion ↗

“S23 gave me the worst sides out of all of them I got permanent acne on my back shoulders chest arms and stomach.”

MixedRead the discussion ↗

Is S-23 safe? What the research covers

AResearch: Strong6 meta-analyses · 26 randomized trials on PubMed

Surg Obes Relat Dis · 2025

Association between metabolic and bariatric surgery and malignancy: a systematic review, meta-analysis, trends, and conclusions

Conclusion: According to the data retrieved from patients who underwent MBS compared to nonoperated patients suffering from obesity, the overall risk for malignancy was lower in the MBS group. Additional information collected in this study revealed the behavior of specific types of cancer in response to induced weight loss by operative means. The benefit of surgery in patients suffering from obesity is not restricted to the improvement of obesity morbidity alone.