Fortetropin,
does it really help with Increased muscle mass and strength and prevention of muscle loss through myostatin inhibition?
research showsFortetropin is rated C with 41 points for claims of increasing human muscle mass or strength and preventing muscle loss. In a 24-person immobilization trial, between-group differences were absent for losses of muscle cross-sectional area, leg lean mass, and isometric peak torque, so the direct outcomes for preservation and strength were null. This was a single small manufacturer-supported trial rather than a large human null trial, however, and an earlier 37-person training trial reported a positive lean-mass signal alongside surrogate signals for myostatin and muscle-protein synthesis. C at the floor of the band denotes limited and conflicting evidence, not demonstrated efficacy.
ads claimMarketing converts circulating myostatin and muscle-protein-synthesis measurements into proven muscle growth, strength improvement, and protection during injury or inactivity. The later human immobilization trial shows that this clinical bridge did not hold.
Useful facts when choosing a product
- Fortetropin is a non-thermally pasteurized, freeze-dried protein-lipid ingredient derived from fertilized egg yolk and used in branded products such as YOLKED.
- Trial doses varied, including 6.6 to 19.8 g per day, and cannot be assumed equivalent to every marketed formulation or serving.
- People with egg allergy should avoid it, and long-term safety evidence is limited in pregnancy, lactation, children, and people with chronic illness or multiple medications.
- The early studies and the pivotal later human trial all received funding or material support from MYOS, leaving no independent replication.
Chamgap Semantic Classification Code
Candidate index · review held
F.fortetropin.food.muscle-mass-and-strength-and-prevention-of-muscle-loss-through-myostatin-inhibition.prevent.placeboFoods and beverages > Fortetropin > Food consumption > muscle mass and strength and prevention of muscle loss through myostatin inhibition > Occurrence-prevention claim > Placebo
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
Sharp and colleagues assigned 45 resistance-trained men to placebo, 6.6 g, or 19.8 g, with 37 completing 12 weeks. Lean mass and muscle thickness increased only in Fortetropin groups, but bench-press and leg-press strength rose equally in every group. Evans and colleagues randomized 20 adults averaging 66 years of age for 21 days and reported an 18% average increase in fractional synthesis across muscle proteins, without testing change in actual muscle mass or strength. Lim and colleagues assigned 24 young men to six weeks of Fortetropin or energy-matched cheese powder, including two weeks of unilateral leg immobilization. Myostatin rose only with placebo, yet losses in muscle area, lean mass, and strength were the same between groups.
Why this is classified as C (41)
C. The 24-person immobilization trial found no between-group benefit for loss of muscle area, lean mass, or peak torque, so direct preservation and strength outcomes were null. Because this was a single small manufacturer-supported trial and earlier lean-mass plus myostatin and muscle-protein-synthesis signals coexist, the evidence is limited and conflicting rather than a large replicated null result, yielding C with 41 points. Egg allergy and limited long-term safety are separate concerns.
Counterpoint. Adequate protein and energy intake, progressive resistance training, rehabilitation, and treatment of the cause remain first-line for muscle gain and preservation. Fortetropin should not replace these methods or be expected to prevent disuse loss.
Rejudgment record. Reassessment (cross-check reflected) — Accepted the null direct atrophy and strength outcomes in the 24-person immobilization trial, but treated them as one small manufacturer-supported result rather than a large replicated null finding because an earlier 37-person trial and mechanistic studies provided positive lean-mass and surrogate signals; applied the floor of C for limited and conflicting evidence
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Increased muscle mass and strength and prevention of muscle loss | C | Direct strength and atrophy outcomes were null in 24 participants, with small and conflicting evidence. |
| Myostatin suppression | ? | This is only a surrogate signal, not a demonstrated clinical benefit. |
| Promotion of muscle-protein synthesis | ? | This is an early small surrogate signal. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Sharp MH et al. 2016 | Twelve-week randomized placebo-controlled resistance-training trial plus rodent mechanistic experiment | 45 resistance-trained men assigned; 37 completed | Funding and product support from MYOS Corporation | Lean mass, muscle thickness, bench-press strength, and leg-press strength | Lean mass and muscle thickness increased in Fortetropin groups, but strength increased equally in all groups. | Early small manufacturer-supported signal with null strength superiority |
| Evans W et al. 2021 | Twenty-one-day randomized double-blind placebo-controlled trial | 20 healthy older men and women | Research funding from MYOS Corporation | Deuterium-labeled fractional synthesis rate of muscle proteins | Average synthesis rates were 18% higher across proteins, but changes in muscle mass and strength were not tested. | Physiologic surrogate from a very small manufacturer-funded trial |
| Lim C et al. 2023 | Six-week randomized controlled trial with two weeks of unilateral leg immobilization | 24 young men assigned; approximately 20 in main analyses | Research funding from MYOS Corporation | Thigh muscle area, leg lean mass, muscle-fiber area, isometric peak torque, and circulating myostatin | The myostatin rise was prevented, but losses of muscle area, lean mass, and strength did not differ from placebo. | Pivotal null trial on direct muscle and strength outcomes |
Receipt — 3 References
All 3 cited sources were verified for existence at the original page (as of 2026-07-19).
Final verification and publication gate: Codex · Evidence date: 2026-07-19 · Corrections: none
Cite this verdict
[Chamgap] Fortetropin x myostatin inhibition, muscle and strength gain, and prevention of muscle loss — Evidence Grade C·41. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/sports/fortetropin-muscle-mass-strength-disuse-atrophy/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.