Tesamorelin
What it is
Tesamorelin is a synthetic, stabilized analog of human growth-hormone-releasing factor (GRF, also called growth-hormone-releasing hormone or GHRH). It carries the 44 amino acid GRF sequence with a hexenoyl group added at the N-terminal tyrosine, a modification intended to resist enzymatic breakdown, which places it in the growth-hormone secretagogue family of peptides.
Research context and categorization
Tesamorelin is generally grouped under the growth-hormone secretagogue category, and by function it also sits within metabolic and visceral-fat regulation research. Rather than supplying growth hormone directly, it is described as acting on pituitary somatotrope cells to prompt the body's own pulsatile release of growth hormone, which in turn influences the growth hormone and IGF-1 axis.
Within its FDA-cleared use, it is applied to the reduction of excess visceral (deep abdominal) fat in people with HIV-associated lipodystrophy. Beyond that specific indication, it is commonly discussed in relation to visceral adipose tissue and its reported selectivity for deep abdominal fat over subcutaneous fat, and it has been investigated for liver fat and non-alcoholic fatty liver disease (NAFLD/MASLD), as well as explored in studies of cognitive function in older adults. These broader areas are investigational research contexts, and outside the approved HIV-lipodystrophy indication the effects are not confirmed or approved outcomes.
Status
- Regulatory status: FDA-approved for a specific indication, the reduction of excess abdominal fat in HIV-infected individuals with lipodystrophy (marketed under the Egrifta family of brand names). Use outside that indication is investigational.
- Sport status: Prohibited under the WADA Prohibited List. It is categorized under S2, Peptide Hormones, Growth Factors, Related Substances and Mimetics, within the growth-hormone-releasing factors subclass, and is prohibited at all times (in-competition and out-of-competition).
Reconstitution notes (general)
Tesamorelin ships as a lyophilized (freeze-dried) powder that is prepared with bacteriostatic water before use. The working concentration follows a simple relationship: concentration equals the milligrams in the vial divided by the millilitres of bacteriostatic water added. For example, 5 mg reconstituted with 2.5 mL gives 2 mg/mL. To check your own numbers, see the calculator at our reconstitution and blend calculators.
Dilution and handling notes (compound-specific)
Reported preparations commonly land around 2 mg/mL, and vial sizes such as 2 mg, 5 mg, and 10 mg are typical in reference material. As illustrative points from that reference range: a 2 mg vial with 1 mL yields about 2 mg/mL, a 5 mg vial with roughly 2.5 mL yields about 2 mg/mL, and a 10 mg vial with 3 mL yields about 3.33 mg/mL. Chosen water volume is largely a matter of the concentration a researcher wants to work with rather than a hard solubility limit, and mixing on the more dilute side is often preferred because it dissolves cleanly and draws precisely.
Tesamorelin generally goes into solution readily and should present as a clear, colorless liquid with no visible particulates or cloudiness once fully dissolved, a process that commonly takes a couple of minutes. It is described as a fragile peptide, so the practical handling emphasis is gentleness: run the bacteriostatic water slowly down the inside wall of the vial rather than aiming the stream directly at the powder, then swirl gently and allow it to dissolve. Vigorous shaking is avoided because it can cause foaming and is thought to stress the peptide chain. If the solution stays cloudy, shows particulates, or fails to clear, that is treated as a sign not to use it. This is a reconstituted lyophilized powder, not an oral tablet, small-molecule liquid, or pre-mixed solution.
Handling and storage
Keep reconstituted solution refrigerated at 2 to 8 C and out of direct light. Wipe the vial stopper with an alcohol swab before drawing, and label the vial with the mix date so the in-use window can be tracked. Reconstituted with bacteriostatic water, a common refrigerated working window is on the order of about four weeks, though some references favor shorter use windows or frozen aliquots for longer holds. Discard any vial that turns cloudy or discolored or that shows floaters or particulates.
Related reading
Tools and supplies
- Reconstitution & blend calculators
- Bacteriostatic Water 30 ml
- Gansulin Metal Reusable Pen
- 3 ml Glass Cartridges (10-pack)
- Complete Starter Kit
For laboratory and research reference only. Educational content, not medical, dosing, injection, or therapeutic guidance, and not intended for human or animal use. Any research uses described are investigational and not confirmed or approved benefits. Confirm anything involving health with a licensed professional. References linked above.