Peptide FAQs

What is Sermorelin?

Sermorelin is a synthetic peptide analogue of human growth hormone-releasing hormone (GHRH). It was developed by the German firm EMD Serono for the treatment of growth hormone deficiency (GHD) in both children and adults. The peptide’s primary function is to stimulate the manufacture and release of growth hormone (GH) in the human body.

Following clinical trials, sermorelin was initially approved by the U.S. Food and Drug Administration (FDA) in 1997 and sold under the trade name “Geref,” indicated for the treatment of growth hormone deficiency (GHD) in both children and adults [1, 2]. Its FDA approval was discontinued in 2008 for commercial reasons unrelated to its safety or efficacy [3].

Sermorelin was also used as a diagnostic agent for assessing whether a given patient’s pituitary gland was functioning properly and releasing adequate amounts of GH [1, 2].

The peptide is now being researched for applications beyond the diagnosis and treatment of hormone deficiency, including for its role in sleep quality, heart health, and even as a novel brain tumor treatment.

What Does Sermorelin Do?

Sermorelin contains the first 29 amino acids of growth hormone-releasing hormone and is the shortest synthetic peptide to offer the full biological activity of endogenous GHRH [4].

As an analog of GHRH, sermorelin also binds to the growth hormone-releasing hormone receptor found in the anterior pituitary gland, signaling to the pituitary gland to produce and release more growth hormone in the body, by way of somatotropic cells.

Sermorelin’s mechanism is different from that of biosynthetic hGH, since injection of the latter can raise GH in the body to supraphysiological levels. On the other hand, the primary function of sermorelin is to mimic native GRF and stimulate GH secretion to the maximum natural level. [4].

Sermorelin Benefits | Clinical Trials

 Effective treatment of adult-onset growth hormone insufficiency: Sermorelin is an effective and attractive treatment of adult-onset GH insufficiency. Unlike rhGH, sermorelin does not stimulate IGF-1 production in the liver and instead stimulates the pituitary gland to produce and secrete endogenous hGH, giving it a number of clinical advantages over exogenous hGH.

Notably, according to a 2006 article by Richard Walker, overdoses of endogenous hGH are “difficult if not impossible to achieve” as the effects of sermorelin are regulated by negative feedback involving the inhibitory neurohormone, somatostatin.

Sermorelin is not associated with the pro-cancer and pro-diabetes side effects linked to long-term hGH therapy, and is thus heavily researched to treat adult-onset GH insufficiency along with being used in longevity medicine for preserving youthful anatomy and physiology [5].

Positive effects on body composition: Sermorelin has been identified as one of several growth hormone secretagogues (GHS) that can help manage body composition in hypogonadal males. In a 2020 paper, Deepankar et al. noted that sermorelin can “significantly improve body composition” (in hypogonadal males) while “ameliorating specific hypogonadal symptoms” such as fat gain and muscular atrophy [6].

While the authors suggest that sermorelin could be used to achieve lean mass gain in both hypogonadal males and men with subclinical hypogonadism, to date, there is no published research that has investigated sermorelin’s effect on body composition in healthy subjects, highlighting an area for further research.

Potential anti-aging benefits: A 1992 study identified sermorelin’s potential anti-aging benefits after nine young male test subjects (22 to 33 years old) and ten elderly male test subjects (60 to 78 years old) were administered the peptide. The study found that short-term subcutaneous sermorelin injections enabled healthy male test subjects to reverse age-related decreases in GH and levels of IGF-I [7].

A 1997 single-blind randomized placebo-controlled trial found that elderly male and female test subjects who received nightly subcutaneous injections of sermorelin for 16 weeks experienced a “significant increase in skin thickness.” The peptide was found to produce significant increases in lean body mass in male test subjects and notable increases in libido and wellbeing. Male test subjects gained an average of 1.26 kg of lean body mass by the end of the trial [8]

Sermorelin and heart health: Sermorelin has been investigated alongside other GHRH agonists as a potential treatment for myocardial infarction scarring in swine [9]. The 2015 study found that sermorelin offered a number of benefits in post-heart attack animal models, which included:

• Reduced remodeling following a heart attack
• Increased growth of blood vessels in damaged tissue
• Reduction in cell death in cardiomyocytes

As a result, there is research interest in sermorelin’s heart health-related benefits, namely in its potential to treat problems resulting from cardiac remodeling and ability to heal damage in myocytes following a heart attack.

Sermorelin Side Effects

According to a review of sermorelin’s use in the diagnosis and treatment of children with GHD, once daily subcutaneous doses of the peptide were well tolerated [4]. The review noted that the most commonly reported adverse events were transient facial flushing and injection site pain.

According to Drugs.com, the most common sermorelin side effects are [10]:

• Facial flushing
• Headache
• Nausea
• Pain
• Redness, or swelling at injection site
• Paleness
• Strange taste in mouth
• Vomiting

Is Sermorelin Safe?

Sermorelin currently lacks FDA approval as its approval was withdrawn in 2008 for reasons other than safety and efficacy [3]. Data on the safety of sermorelin for non-medical uses such as improving body composition in healthy subjects remains lacking.

As noted by Prakash and Goa, while sermorelin is a “well-tolerated” GHRH analogue when used as a provocative test of GHD in children, such tests would involve a single intravenous 1 μg/kg body weight dose and tell us very little about the peptide’s long-term safety [4].

According to Walker, sermorelin is potentially safer than exogenous rhGH because it does not stimulate IGF-1 and is virtually incapable of causing overdose, given that the peptide merely stimulates endogenous hGH and its effects are regulated by somatostatin [5].