GDF-8
also known as Myostatin, MSTN, Growth Differentiation Factor 8
TGF-β superfamily myokine that negatively regulates skeletal muscle growth. Genetic loss-of-function increases muscle mass, reduces adiposity, and improves metabolic health in mice and humans with no known adverse phenotypes. Primary research focus involves inhibition strategies (monoclonal antibodies, active immunotherapy, gene editing) rather than exogenous administration. Studied for sarcopenia, obesity, and muscle wasting conditions.
At a glance
Not administered — research target for inhibition
Primary target — Activin type II receptors (ActRIIA/B) on skeletal muscle [iglesias-2026].
Pathway — MSTN → ActRII/TGFBR1 → Smad2/3 signaling → muscle protein synthesis suppression.
Downstream effect — Restricts muscle hypertrophy, limits satellite cell activation, increases proteolysis via ubiquitin-proteasome and autophagy pathways [gong-2026][iglesias-2026].
Origin — Endogenous myokine secreted by skeletal muscle; circulates systemically as latent complex [iglesias-2026].
Feedback intact — Yes — part of muscle-pituitary endocrine axis; muscle-derived MSTN influences FSH synthesis [iglesias-2026].
| Parameter | Value |
|---|---|
| Clinical use | None — MSTN is a research target for inhibition, not a therapeutic peptide administered to humansSold by research suppliers (e.g., CertaPeptides) for in vitro / animal studies only. |
| Inhibition strategies | Monoclonal antibodies, VLP-based active immunotherapy, gene editing (CRISPR) |
| VLP immunogen (MS2.87-97) | Active immunization protocol in mice — elicits anti-MSTN antibodies without GDF11 cross-reactivity [jacquez-2026]Reduces body fat, increases muscle mass and grip strength; no major safety concerns in animal models. [jacquez-2026] |
| Dual immunization (MSTN + Activin A) | Combined active immunization in GH-deficient mice [mansoor-2026]Improves skeletal muscle performance beyond single-target inhibition. [mansoor-2026] |
| Gene editing outcomes | Precision CRISPR edits produce double-muscle phenotype, improved carcass quality in livestockPleiotropic effects on metabolism, reproduction, and welfare require systematic evaluation. |
Reconstitution
A pure mass-to-volume utility. Enter what you have in the vial; the atlas computes the volume per dose. No prescription information.
Human genetic loss-of-function cohorts · Animal models with MSTN inhibition [herman-2026][jacquez-2026]
| Outcome | Finding |
|---|---|
| Primary mechanism | MSTN loss-of-function reduces fat accumulation independent of muscle mass effects |
| Human genetic evidence | Humans with MSTN function-disrupting variants have increased muscle mass, strength, and reduced adiposity [herman-2026] |
| Animal model outcomes | VLP-immunized mice: reduced age-associated weight gain, significantly lower body fat by DEXA [jacquez-2026] |
| Adipose-muscle crosstalk | MSTN modulates myostatin-TAZ signaling; inhibition shifts adipose expansion toward hyperplasia [li-2026] |
| Metabolic benefits | Improved metabolic health in genetic MSTN null models [jacquez-2026] |
| Age-related effects | MSTN upregulation linked to age-dependent muscle atrophy and fat accumulation |
- — Not applicable — MSTN is not administered as a therapeutic agent
- — Inhibition strategies contraindicated in conditions requiring maintained muscle proteostasis (theoretical)
- 01Research context only
GDF-8 (myostatin) is not administered to humans. It is studied as a target for inhibition using monoclonal antibodies, active immunotherapy (VLP-based vaccines), or gene editing (CRISPR). Research-grade peptide supplied by vendors like CertaPeptides is intended for in vitro and animal studies only.
- 02Inhibition strategies
Clinical development focuses on blocking MSTN activity via: (1) neutralizing monoclonal antibodies targeting mature MSTN or ActRII receptors; (2) active immunotherapy generating endogenous anti-MSTN antibodies (e.g., MS2.87-97 VLP platform); (3) precision gene editing to disrupt MSTN expression in livestock or therapeutic contexts.
- 03VLP immunization protocol (animal model)
MS2.87-97 VLP administered to mice elicits anti-MSTN antibodies targeting a discrete epitope in mature MSTN protein. Immunization schedule and dose optimized for sustained antibody response without GDF11 cross-reactivity. No human protocols established. [jacquez-2026]
- 04Gene editing considerations
CRISPR-mediated MSTN knockout produces double-muscle phenotype in livestock (cattle, swine, sheep). Ethical frameworks and welfare assessments required; pleiotropic effects on reproduction, metabolism, and health must be systematically evaluated before human translation.
Sources
of 48 rendered claims carry a resolvable citation.
- [gong-2026]Gong 2026 — Molecular mechanisms of skeletal muscle atrophy: clinical challenges and future therapeutic strategies.
journal, 2026 - [herman-2026]Herman 2026 — Humans with function-disrupting variants in the myostatin gene (MSTN) have increased skeletal muscle mass and strength, and less adiposity.
journal, 2026 - [iglesias-2026]Iglesias 2026 — Myostatin in the pituitary-muscle axis: Roles in health and disease.
journal, 2026 - [jacquez-2026]Jacquez 2026 — A VLP-based immunogen that elicits selective anti-Myostatin antibodies, enhances muscle mass and strength, and reduces adiposity.
journal, 2026 - [li-2026]Li 2026 — Caffeic acid phenethyl ester ameliorates high-fat diet-induced muscle textural deterioration in grass carp (Ctenopharyngodon idellus) by modulating adipose-muscle crosstalk via myostatin-taz signaling.
journal, 2026 - [mansoor-2026]Mansoor 2026 — Active immunization against myostatin and activin A improves skeletal muscle performance in growth hormone-deficient mice.
journal, 2026