2019;178(6):1299312 e29
As an emergency training professional with a medical foundation, I aim to cut through confusion and arm readers with facts so they can make informed choices about their health
This method avoids first-pass metabolism, which can enhance bioavailability compared to traditional delivery methods
Reported benefits (per available research): Studied for its ability to trigger strong, dose-dependent endogenous growth hormone release, with some human research indicating it releases more GH than growth hormone releasing hormone (GHRH) alone Investigated for potential cardioprotective effects through CD36 receptor binding in cardiac tissue, with preclinical and small experimental work describing improved cardiac function after ischemia, though researchers note clinical trials in humans remain limited May support lean mass, strength, and connective-tissue recovery, a claim attributed to GH/IGF-1-driven protein synthesis rather than to dedicated human bodybuilding trials Explored in preclinical, cell-based research for neuroprotective and antioxidant activity, evidence that is preliminary and non-human Known risks and side effects: Acute elevation of ACTH and cortisol, documented in a small human study, raising theoretical concern about HPA-axis disruption or Cushingoid effects with sustained high-dose exposure Elevated prolactin reported in human research, which in chronic excess is associated with hyperprolactinemia-related effects such as visual disturbance and reproductive or hormonal disruption Water retention, joint discomfort, and increased appetite, effects consistent with other GH-elevating secretagogues Partial, reversible desensitization of the GH response with prolonged daily use in human studies, with sensitivity reported to return after a period off Because it is distributed only as an unregulated research chemical, actual product purity and dosage are unverified, adding contamination and dosing-error risk on top of any physiological effects Evidence snapshot: The strongest human data is a small 1999 clinical study (15 healthy male volunteers) confirming hexarelin's stimulatory effect on GH, ACTH, and cortisol via the HPA axis
or in patients with chronic bronchitis where treatment periods were lengthy (1224 weeks) at doses of 400600 mg/day where NAC reduced the risk of exacerbations and improves symptoms in patients with chronic bronchitis compared with placebo (11 trials, 2,011 participants).(7) Clinical trial evidence for the use of NAC as an antioxidant in influenza and other acute viral respiratory tract infections is limited and relate to isolated small clinical trials
