Tesamorelin is one of the few compounds sold as a research peptide that also has an FDA label, so its side effects are not a matter of anecdote. They were counted, against placebo, in two trials — in one population, for one use, over a fixed period. This page sets out what those tables contain, what FDA's adverse-event database adds, and where the record stops. The dosing side of the same labels is on our tesamorelin dosage page; this page does not repeat it.
Where the numbers come from
There are two current labels, both from Theratechnologies under the same biologics licence (BLA 022505), both effective 2026-07-29 on openFDA:
| Product | Vial | Labelled daily dose | Diluent |
|---|---|---|---|
| EGRIFTA SV | 2 mg | 1.4 mg (0.35 mL) | Sterile water, single dose |
| EGRIFTA WR | 11.6 mg | 1.28 mg (0.16 mL) | Bacteriostatic water, 7 days per vial |
Neither label ran its own safety trials. Both say their safety "has been established based on clinical trials conducted with EGRIFTA (1 mg/vial formulation)" at a 2 mg dose, and that exposure is similar across the three. Those trials enrolled 740 HIV-infected patients with lipodystrophy and excess abdominal fat; 543 received tesamorelin during the 26-week placebo-controlled phase, against 263 on placebo. Every rate below comes from that group.
The labelled table, 26 weeks
The labels print the adverse reactions that occurred in at least 1% of treated patients and more often than on placebo. The first ten:
| Reaction | Tesamorelin (n=543) | Placebo (n=263) |
|---|---|---|
| Injection-site reaction (combined) | 17% | 6% |
| Arthralgia (joint pain) | 13% | 11% |
| Pain in extremity | 6% | 5% |
| Myalgia | 6% | 2% |
| Peripheral oedema | 6% | 2% |
| Paraesthesia | 5% | 2% |
| Hypoaesthesia | 4% | 2% |
| Rash | 4% | 2% |
| Dyspepsia | 2% | 1% |
| Vomiting | 3% | 0% |
The list continues with musculoskeletal pain, general pain and itching (2% versus 1% each), musculoskeletal stiffness (2% versus 0%), and at 1% versus 0%: raised creatine kinase, carpal tunnel syndrome, joint swelling, muscle strain, night sweats and palpitations.
Two things in that table are easy to misread. Joint pain was common on placebo too (11%), so the drug's share of it is a couple of percentage points, not thirteen. And the table's 17% injection-site figure is narrower than the one in the warnings section, which counts 25% on tesamorelin versus 14% on placebo for all injection-site reactions over the same 26 weeks — erythema, itching, pain, irritation and bruising. The labels' only mitigation is to rotate sites across the abdomen.
Why the side effects look like growth hormone's
Tesamorelin is a stabilised copy of growth-hormone-releasing hormone. It makes the pituitary release more of the body's own growth hormone, which raises IGF-1. The labels attribute the joint pain, limb pain, swelling and carpal tunnel syndrome to fluid retention from that growth-hormone rise, "either transient or resolve with discontinuation". Three findings follow from the same mechanism and matter more than the table:
- Blood sugar. By week 26, 5% of treated patients had an HbA1c of 6.5% or higher, against 1% on placebo; the labels give a hazard ratio for developing diabetes of 3.3 (95% CI 1.4 to 9.6) from a mean baseline HbA1c of 5.3%. They tell prescribers to check glucose before and during treatment, and to watch diabetic patients for worsening retinopathy.
- IGF-1 above range. After 26 weeks 47% of patients had IGF-1 more than 2 standard deviation scores above normal and 36% more than 3, visible from week 13. Among those who stayed on for 52 weeks, 34% and 23%. The labels' own sentence: "The effects of prolonged elevations in IGF-1 levels are unknown."
- Cancer precaution. No malignancy signal is reported from the trials; the warning exists because growth hormone and IGF-1 are growth factors. Tesamorelin is contraindicated in active malignancy, and the labels say to stop it on any evidence of recurrence.
Hypersensitivity reactions — itching, redness, flushing, hives, rash — occurred in 4% of trial patients.
Antibodies: half of patients made them
This is the finding the research-peptide market almost never mentions. In the trials, anti-tesamorelin IgG antibodies were detected in 50% of patients after 26 weeks and 47% after 52. In about 60% of those, the antibodies also cross-reacted with the body's own GHRH. Neutralising antibodies — the kind that block activity in a laboratory test — were found at week 52 against tesamorelin in 10% and against human GHRH in 5%. Among patients who had a hypersensitivity reaction, 85% were antibody-positive.
The labels report that fat reduction and IGF-1 response were similar with or without antibodies, and that six months after stopping, 18% of a group that had been antibody-positive still were. What the record does not show is what those antibodies mean for someone who stops and starts repeatedly, or for a product that is not the labelled one.
What FDA's adverse-event database holds
An openFDA query of the FAERS database on 2026-09-28 (data updated 2026-07-30) returned 1,586 reports naming tesamorelin. Where sex was recorded, 357 were men and 66 women — the reverse of most peptide records, and a reflection of who is prescribed Egrifta. 324 were coded serious.
The ten most frequent coded terms are mostly about use rather than reaction:
| Term | Reports |
|---|---|
| Product dose omission issue | 285 |
| Incorrect dose administered | 164 |
| Injection-site pain | 141 |
| Drug ineffective | 128 |
| Product preparation issue | 121 |
| Weight increased | 97 |
| Arthralgia | 95 |
| Injection-site bruising | 89 |
| Therapeutic product effect incomplete | 86 |
| Wrong technique in product usage process | 78 |
A daily injection mixed from powder, in two formulations the labels call "not substitutable", produces dosing and preparation reports; the reactions that appear — injection-site pain and bruising, joint pain — are the ones the trials predicted. FAERS counts do not measure how often anything happens, and they cannot separate cause from coincidence; they show what people reported.
Where the record stops
Tesamorelin's research-vial market is not the population the labels studied. It is sold, usually as a lyophilised powder, to people without HIV lipodystrophy, often alongside other growth-hormone secretagogues, which is the comparison on our tesamorelin vs ipamorelin page. None of the following is in the record:
- Side-effect rates in people without HIV, or in women beyond the trials' small share.
- Any data on tesamorelin combined with ipamorelin, CJC-1295 or other secretagogues.
- Rates for use beyond 52 weeks.
- Anything about the contents of vials sold outside pharmacies — identity, quantity or contamination. Our guide to where peptides come from covers why that cannot be assumed.
The labels' contraindications are specific: disruption of the hypothalamic-pituitary axis (after pituitary surgery, irradiation or head trauma), active malignancy, hypersensitivity, and pregnancy. Anyone weighing tesamorelin, or connecting a symptom to it, should take the question to a prescriber with the label in hand. The same kind of record for its older relative is on our sermorelin side-effects page, and the wider set is indexed on the peptide side-effects overview.
Sources and dates
- EGRIFTA SV (tesamorelin) for injection, Theratechnologies Inc., BLA 022505. openFDA drug label, set id 3d783378-b02d-4f19-99dd-0fc91a042224, effective 2026-07-29. Read 2026-09-28.
- EGRIFTA WR (tesamorelin) for injection, Theratechnologies Inc., BLA 022505. openFDA drug label, set id 839334d3-8c1d-4c26-9036-2ab524a6ea75, effective 2026-07-29. Sections 5, 6.1, 6.2 (immunogenicity) and 12.3. Read 2026-09-28.
- openFDA drug adverse event endpoint, generic name "tesamorelin": total, counts by sex, seriousness and reaction term, run 2026-09-28 (dataset updated 2026-07-30).
- ClinicalTrials.gov search, intervention "tesamorelin": 24 registered studies, 3 recruiting, on 2026-09-28.