Tesamorelin side effects: what the FDA label and trials show

The short answer: the most common tesamorelin side effects in the approval trials were injection site reactions, joint pain, pain in the arms or legs, muscle aches, swelling, and tingling, most of them linked to fluid retention from higher growth hormone. [1] The label also warns about higher blood sugar, raised IGF-1, allergic reactions, and use with cancer, and it rules the drug out in pregnancy and in people with pituitary disorders.

Tesamorelin is FDA approved as Egrifta WR and Egrifta SV for one use: reducing excess abdominal fat in adults with HIV who have lipodystrophy. [1] Almost everything known about its side effects comes from trials in that group. This post covers what the label and the trials report, who should not use it, and what is not known about off-label use. It does not give dosing advice; the label dose for the approved use is on the tesamorelin page.

What are the most common side effects of tesamorelin?

The label's safety data come from 740 adults with HIV and lipodystrophy who took tesamorelin in clinical trials, 543 of them during the first 26 weeks, when a placebo group of 263 was running alongside. [1] The adverse reactions that happened more often on tesamorelin than on placebo in those 26 weeks included: [1]

• Joint pain (arthralgia): 13% on tesamorelin versus 11% on placebo
• Pain in the arms or legs: 6% versus 5%
• Muscle aches (myalgia): 6% versus 2%
• Swelling of the hands, feet, or ankles (peripheral edema): 6% versus 2%
• Tingling (paresthesia): 5% versus 2%
• Reduced sensation (hypoesthesia): 4% versus 2%
• Rash: 4% versus 2%
• Vomiting: 3% versus 0%
• Indigestion, general musculoskeletal pain, and itching: 2% each versus 1%
• Carpal tunnel syndrome, joint swelling, night sweats, and palpitations: 1% each versus 0%

The label groups the most commonly reported reactions into four families: hypersensitivity reactions such as rash and hives, edema-related reactions such as joint pain and carpal tunnel syndrome, high blood sugar, and injection site reactions. [1]

Read the numbers with the placebo column in view. Joint pain was common on placebo too, so tesamorelin added only about 2 percentage points. The clearer differences were swelling, muscle aches, tingling, and injection site reactions.

The individual trials told a similar story. In the first phase 3 trial of 412 patients, overall adverse events did not differ significantly between groups, but more patients on tesamorelin dropped out because of an adverse event. [2] The second trial of 404 patients described the drug as well tolerated. [3] A 2026 meta-analysis of five randomized trials named arthralgia, myalgia, paresthesia, and injection site redness as the adverse events associated with tesamorelin. [8]

What do tesamorelin injection site reactions look like?

Redness, itching, pain, irritation, and bruising where the injection goes in. During the first 26 weeks, 25% of patients on tesamorelin reported an injection site reaction, compared with 14% on placebo. [1] The label advises rotating injection sites across different areas of the abdomen to lower the risk. [1]

The pattern held in a later trial. In a 12 month randomized trial of 61 people with HIV and fatty liver, the tesamorelin group had more local injection site complaints than the placebo group, though none were judged serious. [5]

Why does tesamorelin cause swelling and joint pain?

Because it raises growth hormone, and growth hormone makes the body hold on to fluid. The label describes fluid retention as increased tissue turgor and musculoskeletal discomfort, showing up as edema, joint pain, and carpal tunnel syndrome. [1] It adds that these effects are either transient or resolve when treatment stops. [1]

This is the same family of effects seen with growth hormone itself. A systematic review of growth hormone trials in healthy older adults found more soft tissue swelling, joint pain, and carpal tunnel syndrome in treated groups. [9] Tesamorelin raises growth hormone indirectly, through the pituitary, so the two are not interchangeable; our tesamorelin vs HGH post compares them side by side.

Does tesamorelin raise blood sugar?

It can, for some people. Growth hormone works against insulin, so the label lists glucose intolerance and diabetes as a warning. By week 26, 5% of patients on tesamorelin and 1% on placebo had an HbA1c of 6.5% or higher, the threshold used to diagnose diabetes, and the hazard ratio for developing diabetes was 3.3. [1] Average HbA1c at baseline was 5.3% in both groups. [1]

Averages looked reassuring. The pooled analysis of 806 patients found no clinically meaningful differences in glucose measures between groups at 26 and 52 weeks. [4] A 12 week trial in 53 adults with type 2 diabetes found no change in insulin response, fasting glucose, or HbA1c compared with placebo. [6] The 12 month fatty liver trial also found no difference in fasting glucose or HbA1c. [5]

Both findings can be true at once: the average stayed flat while a small share of people crossed into the diabetes range. Two caveats matter here. The phase 3 trials excluded people with diabetes, people on diabetes drugs, and people with fasting glucose of 150 mg/dL or higher. [1] And the label still tells prescribers to check glucose before starting, monitor it during treatment, and consider stopping in anyone who develops glucose intolerance without a clear benefit. [1] For people with diabetes, it advises regular monitoring for the development or worsening of diabetic retinopathy, because tesamorelin raises IGF-1. [1]

If you take insulin or another diabetes drug, the tesamorelin page lists the label's interaction notes.

What does tesamorelin do to IGF-1?

It raises it, by design. IGF-1 is the growth factor that growth hormone tells the liver to make. In the pooled phase 3 data, IGF-1 rose by an average of 108 ng/mL on tesamorelin versus a small fall on placebo. [4] After 26 weeks, 47% of patients had IGF-1 more than 2 standard deviations above the normal average and 36% were more than 3 above it, seen as early as week 13. [1]

The label states that the effects of prolonged high IGF-1 are unknown. It advises monitoring IGF-1 during treatment and considering stopping in people whose IGF-1 stays persistently high, for example above 3 standard deviations, particularly when the fat reduction is not robust. [1]

Does tesamorelin increase cancer risk?

The label treats cancer as a central caution. Because tesamorelin releases growth hormone, a known growth factor, it is contraindicated in anyone with active malignancy. [1] Any earlier cancer should be inactive with treatment complete before starting, prescribers are told to weigh the higher background cancer risk in people with HIV, and the drug should be stopped at any sign of recurrence. [1] Lifetime carcinogenicity studies in rodents have not been done. [1]

Can tesamorelin cause an allergic reaction?

Yes. Hypersensitivity reactions occurred in 4% of patients in the trials, including itching, redness, flushing, hives, and rash. [1] The label says to stop tesamorelin right away and get prompt medical attention if an allergic reaction is suspected. [1]

Antibodies are common. Anti-tesamorelin antibodies were found in about half of patients treated for 26 or 52 weeks, and in 85% of those who had a hypersensitivity reaction. [1] Patients with and without antibodies had similar visceral fat and IGF-1 responses. [1]

Who should not take tesamorelin?

The label lists four contraindications: [1]

1. Pituitary or hypothalamic disruption: hypophysectomy, hypopituitarism, a pituitary tumor or pituitary surgery, head irradiation, or head trauma.
2. Active malignancy.
3. Known hypersensitivity to tesamorelin or any ingredient in the product.
4. Pregnancy. Visceral fat rises normally in pregnancy, changing it offers no benefit, and rat studies showed harm to offspring. The label says to stop the drug if pregnancy occurs. [1]

Other label cautions:

• Breastfeeding: not advised while taking it. [1]
• Children and teens: not indicated, because it can accelerate growth while growth plates are open. [1]
• Adults over 65: there is no information on use in this group. [1]
• Critical illness: higher mortality has been reported with growth hormone in acute critical illness, so stopping should be considered in critically ill patients. [1]
• Steroid replacement: people taking glucocorticoid replacement for adrenal insufficiency may need a higher dose after starting tesamorelin. [1]

The label also says long-term cardiovascular safety has not been established. [1] For the approved use itself, see HIV lipodystrophy.

What is known about side effects in off-label use?

Much less. Clinics market tesamorelin for fat loss, body composition, muscle, and longevity in people without HIV. None of those is an approved use, and the label says tesamorelin is not indicated for weight loss management. [1]

The main trial outside HIV enrolled 60 adults with abdominal obesity and reduced growth hormone secretion for 12 months. It reported no serious adverse events, no difference in adverse events between groups, and no change in fasting glucose, 2 hour glucose, or HbA1c, while IGF-1 rose. [7] That is one small trial in a selected group. No published trial has tested tesamorelin in healthy, lean adults, so side effect rates in that group are unknown. Our fat loss page grades the options by what was actually tested, and our post on whether tesamorelin builds muscle covers the body composition evidence.

For longevity, the closest evidence is indirect. A systematic review of growth hormone in healthy older adults found small body composition changes alongside more swelling, joint pain, carpal tunnel syndrome, and signs of worsening glucose, and concluded that growth hormone could not be recommended as an anti-aging therapy. [9] Tesamorelin has not been studied as a longevity drug.

Fatty liver is a separate case with trial data, but only in people with HIV: the 12 month trial cut liver fat without worsening glucose, with more injection site complaints than placebo. [5] See fatty liver disease for the full picture.

Tested athletes face a separate risk. Tesamorelin is named on the WADA Prohibited List in section S2 and is prohibited at all times, in and out of competition. [12]

Do side effects go away when you stop?

The fluid-related effects, such as swelling, joint pain, and carpal tunnel syndrome, are described on the label as either transient or resolving after treatment stops. [1] Antibodies fade more slowly: among patients who had them at 26 weeks and were checked 6 months after stopping, 18% still tested positive. [1]

The benefit fades too. Patients switched from tesamorelin to placebo after 26 weeks regained visceral fat, and the improvements were lost quickly. [3] Our tesamorelin before and after post covers that timeline in detail.

Is compounded tesamorelin a lower-risk option?

No. Compounded tesamorelin has no lawful basis. Tesamorelin is a 44 amino acid protein, and on March 23, 2020 FDA deemed the Egrifta application (022505) to be a biologics license. [10] FDA states that biological products are not eligible for the 503A or 503B compounding exemptions, so compounded tesamorelin sold by telehealth and anti-aging clinics has no lawful basis, and Egrifta WR by prescription is the only lawful product. [11] Compounded and research-labeled versions have not been through the trials summarized above, so their side effect profile, purity, and strength are not known in the same way.

The tesamorelin regulatory tracker logs each status change with its source, and the tesamorelin cost page lists dated prices for the approved product. Our tesamorelin prescription guide explains who qualifies, how off-label prescribing works, and what a legitimate visit should check, including the glucose and IGF-1 monitoring the label calls for.

How do tesamorelin side effects compare with other growth hormone peptides?

Tesamorelin has a current FDA label with a placebo-controlled side effect table, built from trials in hundreds of patients. [1] The comparison pages lay out what human safety data exist for each of the others. Compare them directly in sermorelin vs tesamorelin, tesamorelin vs ipamorelin, tesamorelin vs CJC-1295, and tesamorelin vs MK-677, or see all three GHRH and secretagogue options in one table in tesamorelin vs sermorelin vs ipamorelin.

If you are weighing tesamorelin, bring this list to a licensed clinician: your glucose history, any cancer history, pituitary conditions, pregnancy plans, and other medicines, especially steroids and diabetes drugs.