Sermorelin for weight loss: does this peptide work?

If you’ve been looking into medical options for weight loss, you may have come across sermorelin. The injectable peptide is sometimes touted for fat loss and muscle building, but does it really work? The short answer: Taking sermorelin for weight loss may have some benefits, but a whole lot more research is needed before we can definitively say yes. 

Sermorelin is a synthetic peptide that tells the pituitary gland to release more of the body's own growth hormone (GH). This makes it a growth hormone–releasing hormone (GHRH) analog. So, rather than supplementing the body directly with more GH, sermorelin helps the body make more of it naturally.

Levels of growth hormone decrease with age, and some research suggests replacing it may help reduce body fat and  increase muscle. That being said, growth hormone provides the most meaningful benefits in people who have a true growth hormone deficiency. 

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It might. In a small study of 10 postmenopausal women, taking a GHRH analog (not quite sermorelin, but the full-length version of the molecule sermorelin is based on) led to a 16% reduction in belly fat in just three months. Another study using a different GHRH analog found it led to both significant gains in lean body mass and reductions in body fat, particularly around the belly.

That said, research on growth-hormone-boosting therapies and weight loss has been mixed, and not every study has found weight loss benefits.

Overall, the current state of research regarding sermorelin for weight loss is quite limited. Significantly more research is needed — with both more participants and focusing on sermorelin specifically — before we can draw any firm conclusions. 

If you are considering sermorelin for weight loss, it is important to keep expectations realistic, says Fernando Ovalle Jr., MD, obesity medicine specialist and expert contributor and reviewer for Drugwatch.com. "In my experience, if weight loss occurs, it's usually incremental rather than dramatic.

Many of the ways sermorelin may work for weight loss are indirect. It may improve body composition, energy levels, recovery, sleep quality, and exercise tolerance, Dr. Ovalle says. These gains may be more pronounced in people who have lower growth hormone levels to begin with.

Belly fat reduction

Even though the studies done thus far have been performed on GHRH-based therapies rather than sermorelin specifically, , more than one have found that these treatments can reduce body fat. 

“Most clinical experience puts the fat loss at around 3% to 6% of body fat over 12–16 weeks, but what makes that number meaningful is that patients are typically gaining lean muscle at the same time,” says Shannon Arora, MD, family medicine hospitalist and Chief Medical Officer at Arora Health.

Sermorelin's potential effects on body fat may be traced back to growth hormone, Dr. Arora says. Growth hormone helps regulate the body's fat storage, especially around the midsection. "Fat loss people experience on GHRH-based therapies like sermorelin is a side effect of restoring a hormone that naturally declines with age," she says.

Improved muscle performance and recovery

A 2018 review found that growth hormone secretagogues in general (the class of drugs sermorelin belongs to) improve muscle mass. For example, studies of GH secretagogues in older adults have found that six months of treatment  can lead to significant gains in lower body strength. 

Additionally, people who take GHRH secretagogues like sermorelin commonly report faster workout recovery and better muscle tone, Dr. Arora says.

Together, these effects may make it easier to build muscle when exercising. And more muscle usually means a faster metabolism, which can further support weight loss efforts.

A small metabolism boost

Preserving muscle mass is important when losing weight. Doing so helps maintain a person's resting metabolic rate (RMR), which represents how many calories the body burns at rest, and may even help increase it. That means more calories may be burned, reducing the risk of weight gain.

By increasing natural growth hormone levels, sermorelin may (again, more research is needed) help boost muscle mass and metabolism, potentially helping tone the body and burn more calories.

Better sleep quality

If you are wondering what sleep has to do with weight loss, the answer is a lot. People who sleep better tend to lose more weight and fat than people who do not sleep well, according to research on  weight loss programs.

Now back to sermorelin: Dr. Arora says better sleep is one of the first effects people notice after starting sermorelin, often within the first couple of weeks. “Growth hormone secretion is closely tied to deep slow-wave sleep, and restoring that signaling tends to improve sleep quality in a way that has downstream effects on energy, mood, and recovery.”

More data is needed from clinical trials to confirm whether sermorelin reliably improves sleep in practice. If sermorelin is capable of improving sleep, it may have major benefits for weight management. 

Improved mood and energy levels

We all know how hard it is to work out when we feel down. That is another way sermorelin may help support a weight loss journey — by lifting mood. "There is research showing that 20 weeks of GHRH supplementation increased GABA activity in the brain, which is relevant to mood regulation and reducing anxiety," Dr. Arora says.

And if a person is sleeping better thanks to sermorelin, that may also help improve mood and energy levels, Dr. Arora says. When people feel better, they may feel more motivated to stick to their weight loss goals. They might also feel like they have more control over their emotions and be better able to avoid emotional eating, research suggests.

It’s important to keep in mind that the potential connection of sermorelin improving mood, which may then support weight loss, is based on reasonable science but still needs to be demonstrated in clinical studies of sermorelin. As more research comes out, our understanding of sermorelin will continue to improve. 

Sermorelin is generally considered safe, but the existing research is limited. The side effects are usually mild, with injection site reactions being the most common. 

Sermorelin side effects and risks

Sermorelin side effects may include:

• Injection site reactions

• Headache

• Flushing

• Nausea

• Water retention

• Joint pain and muscle stiffness

• Carpal tunnel syndrome

• Changes in blood sugar regulation

"The more clinically important consideration is that sermorelin can modestly reduce insulin sensitivity, so anyone with diabetes or blood sugar concerns needs closer monitoring," Dr. Arora says. To help ensure sermorelin is safe, it is important to share a full health history and any current medications or supplements with a healthcare provider. Longer-term safety data are needed for a better understanding of sermorelin’s safety profile over time.

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Because sermorelin has not been approved for weight loss by the US Food and Drug Administration (FDA), there is no standardized dosing and no published clinical trial has established a dose yet either. A typical range in research and clinical practice is 200–500 mcg, injected subcutaneously, typically in the evening, Dr. Arora says based on her clinical experience.

Dr. Arora says this timing is intentional. “Most of the body's growth hormone is released during deep sleep, so dosing at night aligns with that natural pulse,” she says.

Both Drs. Ovalle and Arora caution that the first thing to know about sermorelin for weight loss is that sermorelin is not FDA-approved for obesity. Sermorelin was originally FDA-approved for growth hormone deficiency in children, but is no longer on the market. So, the only way to get it today is through an off-label prescription at a compounding pharmacy.

“This is not unusual in hormone medicine,” Dr. Arora says, “but it does mean the provider you work with needs to actually understand the literature and monitor appropriately.”

Also, Dr. Arora says, sermorelin works best when paired with a healthy diet and exercise routine. “Every study showing meaningful body composition results involved patients who were exercising and eating reasonably,” she says. “Sermorelin supports that process. It does not replace it.”

As an unapproved medication with limited research, sermorelin weight loss results are generally modest and unpredictable, Dr. Ovalle says. "Sermorelin fits more into the niche of peptide wellness or hormone optimization than evidence-based obesity medicine. The data is nowhere near as strong as what we have for medications like semaglutide or tirzepatide."

Speaking of semaglutide and tirzepatide, there are several evidence-backed weight loss methods, including oral and injectable GLP-1 medications, other weight loss pills, and lifestyle changes.

GLP-1 injections

The FDA has approved three GLP-1 weight loss injections:

• Zepbound (tirzepatide)

• Wegovy (semaglutide)

• Saxenda (liraglutide)

Of these, Zepbound produces the most weight loss — up to 20.9% at 72 weeks with the highest dose. In the same timeframe, Wegovy produced about 14.9% and Saxenda about 8.0% weight loss on average. 

GLP-1 pills

The FDA has also approved two oral GLP-1s for weight loss. These include:

• Foundayo (orforglipron), which produces an average weight loss of 7.5%–11.2% in 72 weeks, depending on the dose.

• Wegovy pill (semaglutide), which produces an average weight loss of 13.6% in 64 weeks.

Other weight loss pills

Finally, the FDA has also approved several non-GLP-1 prescription weight loss pills. These include:

• Qsymia (phentermine-topiramate), which produces up to 10.9% weight loss, on average, in 56 weeks.

• Contrave (naltrexone/bupropion), which produces an average weight loss of about 6% in 56 weeks.

• Xenical (orlistat), which produces an average weight loss of about 3.1% greater than placebo.

Xenical’s active ingredient, orlistat, is also available in lower strengths as over-the-counter Alli.

Lifestyle changes

Lifestyle changes are often recommended, even when taking weight loss medications. That is because pairing a weight loss medication with a healthy diet, regular exercise routine, and other health-focused changes can lead to significantly more weight loss than simply taking the medication.

• Achieve a calorie deficit. Translation: start eating less than you used to. Experts usually recommend starting with 500 fewer calories daily, although your healthcare provider can recommend a specific number.

• Exercise regularly. Aim for at least 150 minutes of moderate-intensity exercise and two resistance-based workouts weekly. 

• Set weight loss goals. Research suggests setting achievable goals — and then meeting them early on — sets you up for more overall weight loss. So start small, be specific, and set new goals as you meet your previous ones. 

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Sermorelin may have some metabolic benefits, but more research is needed before it becomes the next big thing for weight loss. Here is what to remember:

• Sermorelin is a synthetic, injectable peptide that works by telling the pituitary gland to release more growth hormone.

• The research, while limited, suggests that sermorelin could help by boosting muscle gains, reducing belly fat, and improving metabolism.

• Common side effects of sermorelin include injection site reactions, nausea, headaches, facial flushing, and carpal tunnel syndrome.

• Today, sermorelin is not FDA-approved for weight loss, and can only be accessed through a compounding pharmacy.

• Other FDA-approved, evidence-backed options for weight loss include oral and injectable GLP-1s and weight loss pills.