Tesamorelin results timeline: what trials measured, week by week

Tesamorelin results in trials were measured in weeks and months: blood growth hormone and IGF-1 rose within 2 weeks, while the main result, less visceral (deep belly) fat, was measured at 26 weeks. In the two phase 3 trials, visceral fat fell 18% and 14% at 26 weeks, against a 2% rise and a 2% fall on placebo [Approved label, Human RCTs, n=412 and n=404] (Egrifta WR label). Tesamorelin is FDA-approved as Egrifta only for excess abdominal fat in adults with HIV and lipodystrophy, and the fat came back after it was stopped.

Item	Status
US FDA status	Approved: Egrifta SV and Egrifta WR (BLA 022505, first US approval 2010) for excess abdominal fat in adults with HIV and lipodystrophy; “not indicated for weight loss management” (label, updated 2026-07-29)
Compounding (503A/503B)	Not eligible: Egrifta is now licensed as a biologic (BLA), and products that moved to BLAs on 2020-03-23 lost the 503A/503B compounding exemptions (FDA)
WADA	Prohibited at all times, S2 peptide hormones and growth hormone releasing factors (WADA 2026 List; USADA). The 2027 List, in force 2027-01-01, describes no change to this class (USADA 2027 advisory)
Strongest evidence	Approved label; two phase 3 placebo-controlled RCTs (816 people with HIV, 26 weeks plus a 26-week extension)
Human trials	24 records on ClinicalTrials.gov (searched 2026-10-28), phase 3 incl. NCT00123253 and NCT00608023
Last checked	2026-10-28 (status sources re-verified 2026-10-28)

Tesamorelin results timeline at a glance

Tesamorelin is a lab-made version of growth hormone-releasing hormone (GHRH), the brain signal that tells the pituitary gland to release growth hormone. Growth hormone then raises IGF-1, a growth factor made mostly in the liver. The table lists the time points that trials actually measured, earliest first. The figures come from different trials in different groups of people, so they are cross-trial figures, not one continuous curve, and no trial measured results day by day.

Time point	What was measured	Evidence level
2 weeks	Growth hormone release and IGF-1 up (Makimura 2011)	Human, single group (n=13)
2 weeks	Fasting glucose up 9 vs 2 mg/dL; no longer different at 6 months (Stanley 2014)	Human RCT (n=50)
12 weeks	No change in glucose control in type 2 diabetes (Clemmons 2017)	Human RCT (n=53)
13 weeks	IGF-1 above 2 SDS seen as early as this (label)	Approved label
20 weeks	Cognition score better than placebo in older adults (Baker 2012)	Human RCT (n=152)
26 weeks	Visceral fat -18% and -14% vs +2% and -2% (label)	Approved label, 2 RCTs
26 weeks	Liver fat down vs placebo (Stanley 2014)	Human RCT (n=50)
52 weeks	Visceral fat loss held at -18% on continued use (Falutz 2008)	Human RCT extension
52 weeks	Visceral fat back up 22% and 16% after a switch to placebo (label)	Approved label
12 months	Liver fat -37% relative to baseline (Stanley 2019)	Human RCT (n=61)

Weeks 1 to 4: hormone levels change first

The first measurable change is in the blood. In a 2-week study of 13 men, tesamorelin increased the body’s own growth hormone release and IGF-1 (Makimura 2011, Human, single group). That fits how it works: it acts on the pituitary rather than replacing growth hormone, so the hormone signal moves within days to weeks while body fat changes much more slowly. Adiponectin, a fat-tissue hormone tied to insulin sensitivity, did not change in those 2 weeks.

Blood sugar can also move early. In a 6-month randomized trial of 50 adults with HIV, fasting glucose rose 9 mg/dL on tesamorelin against 2 mg/dL on placebo at week 2; by 6 months the difference was no longer significant (Stanley 2014, Human RCT, n=50). No trial in this guide reported a visible fat-loss result in the first month.

Months 3 to 6: when visceral fat loss was measured

The benefit tesamorelin is approved for was measured at 26 weeks. In the first phase 3 trial, 412 adults with HIV and excess belly fat (86% men) were randomized to tesamorelin or placebo; visceral fat on CT fell 15.2% on tesamorelin and rose 5.0% on placebo, triglycerides fell 50 mg/dL, and IGF-1 rose 81.0% (Falutz 2007, Human RCT, n=412). The FDA label’s own analysis of the same trial gives -18% against +2%, and -14% against -2% in the second trial of 404 people (Egrifta WR label, Approved label). The second trial’s paper reports -10.9% against -0.6% over its 6-month efficacy phase, with less distress about belly appearance (Falutz 2010, Human RCT, n=404).

The 26-week change was in body shape more than in weight. Weight changed by -0.4 and +0.5 kg, waist circumference shrank by 2 to 3 cm, trunk fat fell 0.8 to 1.0 kg and lean body mass rose 1.2 to 1.3 kg (Egrifta WR label, Approved label). Among people whose visceral fat fell at least 8%, CT scans at 26 weeks also showed denser trunk muscles and 0.64 to 1.08 cm² more lean muscle area than placebo (Adrian 2019, secondary analysis of RCTs, n=341).

Not everyone responds. A pooled analysis of both phase 3 trials found no factor that predicted response at 3 months; at 6 months the authors linked metabolic syndrome, high triglycerides and white race to a greater likelihood of response, and the odds of getting visceral fat below 140 cm² were 3.9 times those on placebo (Mangili 2015, pooled RCT analysis, n=806). The label tells prescribers to weigh continuing in people whose visceral fat has not dropped.

Liver fat also fell by 6 months: in the 50-person trial, the net treatment effect was -2.9% in the liver lipid-to-water percentage, alongside 42 cm² less visceral fat than placebo (Stanley 2014, Human RCT, n=50).

Months 6 to 12: what holds and what fades

In the extension phases, people already on tesamorelin were randomized again at week 26. Those who stayed on it kept a visceral fat reduction of about 18% at 52 weeks, with triglycerides 51 mg/dL lower than at the start (Falutz 2008, Human RCT extension). The label’s figures for weeks 26 to 52 show the other side: visceral fat rose 22% and 16% in the groups switched to placebo, while it stayed flat or fell 5% in those who continued (Egrifta WR label). The authors’ conclusion is plain: the effects “do not last beyond the duration of treatment.”

Responders also showed metabolic gains by 52 weeks. People with at least 8% less visceral fat had larger triglyceride drops (-0.8 vs 0.0 mmol/L) and steadier fasting glucose (-1 vs +8 mg/dL) than non-responders (Stanley 2012, post hoc analysis of RCTs).

The most promising newer result is in fatty liver disease. In a 12-month randomized trial of 61 adults with HIV and fatty liver, liver fat fell 37% relative to baseline, and 35% of the tesamorelin group against 4% of the placebo group ended with liver fat under the 5% threshold (Stanley 2019, Human RCT, n=61). A subgroup on integrase-inhibitor HIV drugs saw visceral fat fall 25 cm² against a 14 cm² rise on placebo over 12 months (Russo 2024, RCT subgroup, n=38). Fatty liver is not an approved use.

Outside HIV, one 12-month randomized trial in 60 adults with abdominal obesity and low growth hormone found 35 cm² less visceral fat than placebo, plus lower triglycerides and C-reactive protein, with no change in glucose (Makimura 2012, Human RCT, n=60). That is a single trial, not an approval for weight loss.

Other outcomes: cognition, muscle and the “before and after” question

In 152 adults aged 55 to 87, 20 weeks of tesamorelin improved a combined cognition score compared with placebo (P=.03), mainly executive function, and cut body fat by 7.4% (Baker 2012, Human RCT, n=152). Tests were run at weeks 10 and 20 and after a 10-week washout. A 2025 trial in 73 adults with HIV did not repeat a cognition benefit at 6 months, though waist size fell 2.7 cm more than with usual care (Ellis 2025, open-label RCT, n=73).

Searches for “tesamorelin before and after” usually mean photos. The trials measured visceral fat on CT scans, a change that a waistline shows only partly: the average waist change at 26 weeks was 2 to 3 cm (label). Results in women are covered separately in tesamorelin for women: evidence, side effects and safety; most phase 3 participants were men (86% and 84%).

Can tesamorelin be combined with ipamorelin or retatrutide?

People ask about a “tesamorelin and ipamorelin results timeline” and a tesamorelin plus retatrutide combination. No controlled human study of tesamorelin with retatrutide or with ipamorelin was found on PubMed or ClinicalTrials.gov (searched 2026-10-28; the ipamorelin search returned only review articles), so no timeline for either combination exists. Retatrutide is an investigational drug, not approved and not legally obtainable outside clinical trials; its own trial results are in retatrutide vs tirzepatide vs semaglutide. How tesamorelin’s evidence compares with the CJC-1295 and ipamorelin pairing is set out in tesamorelin vs CJC-1295 + ipamorelin for fat loss, and against sermorelin in ipamorelin vs sermorelin vs tesamorelin.

Safety and regulatory status

The label’s side effects appear on a similar timescale to the benefits. Over the first 26 weeks, injection site reactions affected 17% of people on tesamorelin against 6% on placebo, and joint pain 13% against 11%; the most common reactions also include limb pain, peripheral swelling (edema) and muscle pain (Egrifta WR label, Approved label). Fluid retention, including carpal tunnel syndrome, is described as transient or resolving after stopping.

Two risks build over months. IGF-1 rose above 2 standard deviation scores in 47% of people by 26 weeks, seen as early as week 13, and “the effects of prolonged elevations in IGF-1 levels are unknown.” HbA1c reached the diabetes range (6.5% or higher) in 5% against 1% on placebo. The label also warns of a possible increased risk of tumors, because growth hormone is a growth factor, and says long-term cardiovascular safety has not been established. It is contraindicated in pregnancy (rat offspring developed hydrocephaly), in active cancer and in people with pituitary disorders (Egrifta WR label). In the first phase 3 trial, more people on tesamorelin than on placebo left the study because of an adverse event (Falutz 2007).

Regulation: tesamorelin is approved in the US only as Egrifta for the HIV indication. Because Egrifta became a licensed biologic, it cannot be compounded under the 503A or 503B exemptions (FDA). For athletes, USADA lists tesamorelin among peptide hormones and growth factors that are prohibited at all times (USADA), under S2 of the WADA 2026 List.

Anyone who suspects a side effect from tesamorelin or any other drug or product can report it to the FDA through MedWatch.