MOTS-c and Tesamorelin both appear in 'metabolic peptide' stacks but work via completely different mechanisms. MOTS-c is a mitochondrial-derived peptide regulating insulin sensitivity; Tesamorelin is a GHRH analogue stimulating GH/IGF-1.
MOTS-c
Tesamorelin
Origin
Encoded in mitochondrial DNA
Modified hypothalamic GHRH
Length
16 aa
44 aa
Molecular weight
~2174 Da
~5135 Da
Mechanism
AMPK activation, insulin sensitivity
GHRH receptor → GH/IGF-1
Research focus
Metabolic, exercise capacity
Visceral adipose tissue reduction
Approval status
Research only
FDA approved (Egrifta) for HIV lipodystrophy
Typical dose
5-10 mg weekly (subcut)
2 mg daily (subcut)
Identity (LC-MS) mass
~2174 Da
~5135 Da
Verdict
Different targets, different doses, no overlap in mechanism. Most AU buyers stack them rather than substitute. The 3000 Da mass gap means LC-MS identity is trivial to verify; failures are almost always under-fill, not substitution.
Frequently asked questions
Can I stack them?
Many users do - different mechanisms, no known interaction. Confirm both vials independently.
Why is Tesamorelin more expensive?
It's an approved pharmaceutical (Egrifta) - real material is harder to source than MOTS-c.