Sermorelin Side Effects: What to Expect and When to Call

By the ShopMedRx team. For adults 18 and older. This article is for education and is not medical advice.

The most common sermorelin side effects are local: pain, redness or swelling where the injection goes in. Less often, people report headache, flushing, dizziness, nausea or sleepiness, and rarely an allergic reaction.^[1][2] Sermorelin is a prescription medicine, and a licensed clinician decides whether it is appropriate for you after reviewing your health history.

This guide goes through each side effect of sermorelin that has been documented, which ones need urgent care, what the studies actually found, and why the quality of a compounded product matters. It is a deeper look at one topic from our Peak Recovery Injection (sermorelin) program page, which explains how the program works.

Sermorelin side effects at a glance

Sermorelin is a peptide that signals the pituitary gland to release growth hormone. Most of what is known about its side effects comes from an earlier FDA-approved sermorelin injection that is no longer sold, plus small studies in adults. The table below groups what those sources describe.^[1][2][6]

Effect	How it is described	What to do
Pain, redness or swelling at the injection site	The most common effect; about 1 in 6 people in label-reported trials[2]	Rotate sites as directed; call your clinician if it lingers or spreads
Itching, trouble swallowing	Listed as rare[1]	Contact your clinician promptly
Dizziness, flushing, headache, sleepiness, trouble sitting still	Listed as rare; may fade as the body adjusts[1]	Tell your clinician if they continue or bother you
Nausea, facial flushing	Noted as rare in older adults in a placebo-controlled trial[6]	Report them at your check-in
Hives, rash, swelling of face, lips or tongue, trouble breathing	Serious allergic-type reactions[2]	Get emergency help right away

Common sermorelin side effects

Injection site reactions

Sermorelin is given by injection. In the label information for the earlier approved sermorelin injection, the most common treatment-related problem was a local reaction with pain, swelling or redness, seen in about 1 patient in 6. Of 350 patients exposed in clinical trials, three stopped treatment because of these reactions.^[2]

The same label says injection sites should be rotated periodically.^[2] Mayo Clinic also notes that a health care professional may be able to suggest ways to prevent or reduce side effects.^[1] Follow the exact directions on your prescription label and the instructions from your clinician and pharmacy.

Headache, flushing, dizziness and sleepiness

Mayo Clinic lists dizziness, flushing, headache, sleepiness and trouble sitting still as rare effects. It advises checking with a health care professional if they continue or are bothersome.^[1] The label summary adds hyperactivity, each occurring in less than 1% of patients in the trials.^[2]

It helps to note when a symptom shows up. A short log of the time of the injection, the symptom and how long it lasted gives your clinician something concrete to work with.

Nausea, taste changes and chest tightness

The label summary lists nausea, vomiting, changes in taste, pale skin and chest tightness. Those particular effects were noted when sermorelin was given intravenously for diagnostic testing, which is a different use from the injection prescribed for treatment.^[2] Even so, tell your clinician about any chest tightness. If it comes with trouble breathing, call 911.

Sermorelin acetate side effects that need urgent care

Sermorelin acetate is the salt form of the peptide, and its serious reactions are allergic in nature. The label summary lists rash, hives, difficulty breathing and swelling of the face, mouth, lips or tongue as serious and says to get medical help right away.^[2] The same source says sermorelin should not be used by people with a known sensitivity to it or its ingredients.^[2]

Is any side effect of sermorelin an emergency?

Yes, a few are. Treat these as emergencies and do not wait for a clinic appointment:

• Trouble breathing or swallowing, or a tight feeling in the throat or chest
• Swelling of the face, lips, mouth or tongue
• Hives or a rash that spreads beyond the injection site

Call your clinician the same day for less urgent warning signs, such as a hard lump that does not go away, drainage from the site, or redness and warmth that keep spreading. These can mean an infection or a stronger local reaction and should be looked at in person.

What studies found about sermorelin peptide side effects

Evidence in adults is limited, so it helps to know the sources. A published review describes a randomized, placebo-controlled trial in 19 men and women aged 55 to 71 who received sermorelin injections for 16 weeks after a 4-week placebo period. The review reports that nausea, facial flushing and redness at the injection site were rare.^[6] That is a small study with a short follow-up, and individual results vary.

The label summary also reports two findings worth knowing about:

• Thyroid: in clinical studies, hypothyroidism developed in 6.5% of patients during sermorelin therapy.^[2] This is one reason clinicians may ask about thyroid history and may order blood tests.
• Antibodies: many patients developed antibodies to the peptide at least once. The label says their meaning was not clear and they did not seem linked to a specific set of adverse reactions.^[2]

Mayo Clinic stresses regular check-ups so a clinician can follow your progress.^[1] Long-term safety data in healthy adults are thin, which is a good reason to treat follow-up visits as part of the plan, not an optional extra.

Why a compounded product adds a quality question

The sermorelin injections that were once FDA-approved were discontinued by their manufacturer in 2008. A report prepared for FDA says this was for reasons not related to safety or efficacy.^[3] Today, sermorelin from a pharmacy is a compounded medication. Compounded medications are not FDA-approved, and the FDA does not review them for safety, effectiveness or quality before they are marketed.^[4]

That matters for side effects in two ways. First, the data above come from studies of a different, previously approved product, so they may not predict exactly what you experience. Second, FDA warns that poor compounding practices can cause drug quality problems, such as contamination or the wrong strength, which can lead to serious injury.^[4] If you notice an unusual reaction, report it. FDA encourages people to tell their health care professional and to report problems with compounded medications to FDA directly.^[5]

At ShopMedRx, independent licensed clinicians (through OpenLoop Health) decide whether a prescription is appropriate, and licensed U.S. partner pharmacies fill it. If you want to check how we operate, see our post on how to verify ShopMedRx.

Practical steps to reduce problems

1. Share your full history. Mention allergies, thyroid conditions, cancer history, pregnancy or plans for pregnancy, and every medicine and supplement you take. Your clinician decides what is safe for you.
2. Rotate injection sites. The label says to rotate them periodically.^[2] Ask your pharmacy or clinician which areas are right for you.
3. Keep a simple symptom log. Note the date, time, symptom and duration. Patterns are easier to spot on paper.
4. Do not change the dose or timing on your own. Your clinician sets the directions. If a side effect is bothersome, ask whether to adjust, pause or stop.
5. Keep your follow-ups. Mayo Clinic notes it is very important that your doctor checks your progress at regular visits.^[1]
6. Check the label. Make sure the name, strength and directions match what your clinician prescribed, and ask the pharmacy if anything looks wrong.

Questions to ask a licensed clinician

• Is sermorelin appropriate for me, given my health history and current medicines?
• Because use in adults is off-label, what are the limits of the evidence for my situation?
• Should I have any blood tests before starting or during treatment, such as thyroid tests?
• Which symptoms should make me stop and call you, and which mean I should call 911?
• How and where should I inject, and how do I store the medicine?
• How will we decide whether to continue, adjust or stop?

Frequently asked questions

What are the most common side effects of sermorelin?

Injection site pain, swelling and redness are the most common. In label-reported trials of the earlier approved injection, about 1 patient in 6 had a local reaction.^[2] Headache, flushing, dizziness and sleepiness are listed as rare.^[1]

Do sermorelin side effects go away?

Mayo Clinic says some side effects may go away during treatment as your body adjusts.^[1] If a symptom continues, gets worse or bothers you, check with your clinician rather than waiting it out.

Can sermorelin cause an allergic reaction?

It can. The label summary lists rash, hives, difficulty breathing and swelling of the face, mouth, lips or tongue as serious effects that need immediate medical help.^[2] People with a known sensitivity to sermorelin or its ingredients should not use it.

Are the side effects of sermorelin different when it is compounded?

The documented effects come from studies of a different, previously approved product. Compounded drugs are not FDA-approved, and FDA does not review them for safety, effectiveness or quality.^[4] Differences in strength or quality are possible, so report anything unexpected.

Does sermorelin affect the thyroid?

The label summary reports that hypothyroidism occurred in 6.5% of patients in clinical studies.^[2] Tell your clinician if you have a thyroid condition or take thyroid medicine, and ask whether monitoring makes sense for you.

Who should not take sermorelin?

Anyone with a known allergy to sermorelin or its ingredients should not use it.^[2] Whether it is appropriate for you also depends on your history, so a licensed clinician needs to review it before any prescription.

Talk to a licensed clinician

Side effects are only one part of deciding whether sermorelin fits your situation. A licensed clinician can review your history, answer questions about risks and decide whether a prescription is appropriate. Approval is not guaranteed, and you should talk with a clinician before starting, stopping or changing any treatment.

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Important information

• This article is for general education and is not medical advice. Talk to a licensed clinician before starting, stopping or changing any treatment.
• All medications available through ShopMedRx are prescription only and are prescribed only if appropriate after a licensed clinician's review.
• Some medications we offer are compounded. Compounded medications are not FDA-approved, and the FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed. They are not the same as, or generic versions of, brand-name drugs.
• Individual results vary. Nothing in this article promises a specific result.
• Prescriptions are written by independent, licensed clinicians through OpenLoop Health and filled by licensed U.S. partner pharmacies.

Sources

1. Mayo Clinic. Sermorelin (injection route): side effects and dosage. Mayo Clinic Drugs and Supplements, accessed 2026-10-11.
2. RxList. Sermorelin acetate: side effects, warnings and precautions (summary of prescribing information). RxList, accessed 2026-10-11.
3. Report prepared for the U.S. Food and Drug Administration. Summary report: sermorelin acetate. University of Maryland Health Sciences and Human Services Library archive, accessed 2026-10-12.
4. U.S. Food and Drug Administration. Understanding the risks of compounded drugs. FDA, accessed 2026-10-11.
5. U.S. Food and Drug Administration. Consumer and health care professional information on compounded drugs. FDA, accessed 2026-10-11.
6. Review of growth hormone secretagogues in hypogonadal males. Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. PubMed Central (PMC7108996).