What Tesamorelin is
Tesamorelin is a stabilized analog of growth-hormone-releasing hormone (GHRH), FDA approved as Egrifta for HIV-associated lipodystrophy. It works by prompting the pituitary to release its own growth hormone pulse, which is why its clinical effect long outlasts its sub-hour plasma half-life.
What we do not know
- Its approval and nearly all its trial evidence are specifically for visceral fat in HIV-associated lipodystrophy. Use in people without that condition is not what was studied.
- Cognitive claims rest on small studies and are not established.
- Visceral fat returns after discontinuation; no strategy to prevent that has been shown.
Reconstitution math
Concentration is everything: the same 5 mg vial gives a different draw for every amount of bacteriostatic water you add. The table uses the common 2 mL setup for each vial size, which puts every unit on a U-100 insulin syringe at 25 mcg for the default vial. Dashes mark draws too small to measure or larger than the syringe.
| Vial | BAC water | Concentration | 1 mg | 2 mg |
|---|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL | 40 u | 80 u |
| 10 mg | 2 mL | 5 mg/mL | 20 u | 40 u |
Dosing and protocol
Egrifta label dose is 2 mg subcutaneously once daily; 1 mg is a common lower start.
The label dose is 2 mg once daily by subcutaneous injection; community protocols often start at 1 mg. Because the peptide clears in hours, timing matters more than accumulation: it is usually taken at night to ride the natural GH pulse, and there is no meaningful carryover from dose to dose.
Pharmacokinetics
Tesamorelin has published human pharmacokinetics: absorbed and cleared within hours; half-life 26 to 38 minutes. The curves below are normalized one-compartment models built from the cited half-life, the same math the Planner uses. They show shape and timing, not absolute blood levels.
How it is thought to work
A stabilized GHRH analog. Rather than supplying growth hormone it stimulates the pituitary to release its own, which preserves pulsatile secretion and the feedback loop that exogenous hGH bypasses.
What the evidence supports
This table grades how well each outcome has been studied in humans, not how well Tesamorelin works. A strong grade means the question was asked properly, and the answer may still have been negative. Nothing here is inherited from a drug class, a close analog, or the parent molecule of a fragment.
| Outcome | Strongest published evidence |
|---|---|
| Visceral fat reduction in HIV lipodystrophy | Human RCT |
| Cognitive function | Human, observational |
| Visceral fat reduction in other populations | Human, observational |
Storage and handling
Lyophilized vials keep best cold, dark, and dry; refrigeration is the community default and freezing lyophilized powder is common for long holds. After reconstitution, refrigerate at 2 to 8 C, do not freeze the solution, and date the vial. Bacteriostatic water's preservative keeps multi-dose use practical for about 28 days by USP convention, though our 120-day stability study found the preservative itself outlasts that window.
Egrifta's own labeling is unusually strict: reconstituted solution should be used right away or discarded. Multi-dose community use of generic tesamorelin vials runs against that guidance; keep reconstituted vials cold and short-lived.
Got a certificate of analysis with your vial? Run it through our COA Reader: it reads the report in plain English, checks purity and mass against the label claim, and links the testing lab’s own verification page. Our guide to reading a COA explains what the numbers do and do not tell you.
Sources
- Egrifta prescribing information (Theratechnologies, 2019)Prescribing information
- Falutz et al., Tesamorelin in HIV-associated abdominal fat accumulation, NEJM 2007