Muscle building and preservation

Source date: 2026-10-21. Recorded in this review: October 27, 2026.

Published October 21: A prospective cohort followed 186 postmenopausal women with osteoporosis and risk factors for sarcopenia: 82 received denosumab and 104 zoledronic acid through routine physician choice, not random allocation. At 36 months, mean grip-strength changes were +2.52 ±0.63 versus +0.99 ±0.45 kg (standard deviations). Appendicular lean-mass index did not differ at 12 months; later group differences favored denosumab. The study-defined classification retrospectively incorporates AWGS 2025 criteria in a cohort recruited in 2020–22.

Propensity-weighted analyses address measured treatment-selection factors but cannot remove unmeasured confounding. Attrition and changing denominators matter: 36-month cumulative falls were 16/60 versus 25/69 (p=.262), and new fragility fractures 3/60 versus 7/69 (p=.337); neither comparison was statistically significant. Comparative adverse-event rates were not provided in the appraised report. This is an association, not proof of a muscle indication or improved fracture prevention. U.S. osteoporosis use is distinct from investigational muscle applications. The separate 20-woman MITO randomized registry result has a different population/duration and should not be pooled with this cohort. No confirmatory-trial readout date verified.

Sources: primary source; ClinicalTrials.gov · NCT05666310.

Source date: 2026-10-23. Recorded in this review: October 27, 2026.

Registry first posted October 23: McGill’s NCT07891156 is a randomized quadruple-masked Phase 2/3 trial planning 40 adults aged 18–65 with type 1 diabetes, BMI ≥27, insulin treatment and CGM. Weekly semaglutide titrates from 0.25 mg toward 2.4 mg if tolerated, versus placebo over 24 weeks. Total lean mass in kg is primary; appendicular lean tissue, fat mass, strength, walking performance and glycemic measures are separate outcomes. Hypoglycemia, ketones and ketoacidosis require specific safety assessment.

Status and limits: The registry says recruiting but retains an estimated October 13 start rather than confirmed actual dosing. The placebo description and a bone-density unit contain inconsistencies and are not copied as validated dosing/measurement instructions. There are no results. DXA lean tissue is not skeletal muscle, and a lean-mass change is not strength or function. This is not an approval of semaglutide for T1D or a substitute for insulin. Estimated primary completion September 1, 2028 and final completion October 1, 2028 are not public-readout commitments.

Sources: primary source.

Related findings, recorded once: MITO posts a small randomized test of osteoporosis drugs and muscle outcomes (primary source).

Coverage and remaining gaps: focused_partial. COURAGE full in-press manuscript and complete BELIEVE withdrawal tables remain unrecovered. Trial-level worldwide coverage and independent functional follow-up remain incomplete.

Informal-source coverage: The enobosarm Cantor Phase 3 planning remark remains unconfirmed; no original new human result or first dosing corroborated. Reposts are not independent confirmation.

Full coverage record.

October 20 update — NCT07777575. The randomized trial of tirzepatide with or without supervised resistance training now reports an actual October 7, 2026 start, replacing the September 7 estimate. Planned enrollment remains 150; primary/final completion moves from May 31 to August 31, 2027. Those are registry estimates, not publication promises.

The primary endpoint is MRI-measured contractile thigh-muscle volume at 24 weeks. The training arm adds three weekly sessions; both groups receive medication and lifestyle counseling. Functional outcomes must be assessed separately from tissue volume. No patient results or trial-specific harms are posted. This is a behavioral add-on study with an approved drug, not a new muscle-building drug approval.

Sources: ClinicalTrials.gov · NCT07777575.

Coverage and remaining gaps: October 20 registry review retrieved all named records and every page of September 5–October 20 discovery (27 records). October 23 extended discovery through October 21–23 (2 records) and rechecked selected priority programs. All retrieval errors were resolved. Retrieval is not exhaustive appraisal: worldwide registries, all primary publications/harms, conference posters and original recordings remain incomplete. Earlier full successful-check dates are preserved. COURAGE full in-press publication and BELIEVE withdrawal-phase detailed safety remain unrecovered.

Informal-source coverage: Targeted original Reddit, interviews, podcasts and saved unresolved-claim searches were checked selectively on October 20 and October 23. Reposts, product promotion and anecdotes do not establish a formal efficacy/safety result; comprehensive original audio/transcript coverage remains incomplete. Enobosarm Cantor Phase 3 direction remains unconfirmed; original recording and actual Phase 3 initiation were not verified. COURAGE reposts repeat the October 1 sponsor report.

Full coverage record.

First posted October 13, 2026. Satellos registers NCT07872306, a masked phase 2 trial planning 51 adults with genetically confirmed facioscapulohumeral muscular dystrophy (FSHD1/2). Oral forazapadin/SAT-3247, an AAK1 inhibitor, 60 or 120 mg is compared with placebo. Primary outcomes are treatment-emergent adverse events through 48 weeks and dynamometry muscle-force change at 24 and 48 weeks. Functional, disease-specific outcomes cannot be generalized to healthy muscle building or weight-loss treatment.

Status/safety/U.S.: Not yet recruiting; no results or adverse-event rates. The protocol excludes recent GLP-1/GIP treatment. Registration is not marketing approval. Timing: December 15, 2026 estimated start; December 30, 2028 primary and June 30, 2029 final completion, all registry estimates rather than promised readouts.

Sources: ClinicalTrials.gov · NCT07872306.

Remaining gaps: All saved named registry records retrieved and all pages of bounded September5/6–October13 CT.gov discovery downloaded; 25 records screened selectively. Retrieval is not full appraisal. Worldwide registries, all publications/regulatory files, comprehensive harms and full audio/transcripts remain incomplete; prior full successful-check dates preserved. COURAGE in-press full journal tables and BELIEVE withdrawal harms remain unrecovered; PPMD October7 original replay not appraised.

Informal-source coverage: Original October1 COURAGE Reddit repost and October7 program comment were revisited; neither is new confirmation. Enobosarm Cantor direction remains a third-party account; original audio and actual phase3 initiation unverified. Gray-market sourcing discussion excluded.

Full coverage record.

Source date: October 1, 2026; newly appraised October 9. Evidence: sponsor/conference report, not a fully appraised journal publication. In COURAGE (NCT06299098), the low-dose portion continued semaglutide 2.4 mg plus placebo, trevogrumab 25 mg or 75 mg for 52 weeks. DXA lean-mass changes were −7.3% (95% CI −8.8 to −5.8), −5.8% (−6.8 to −4.7) and −4.2% (−5.3 to −3.1), respectively. Those are arm-specific intervals, not intervals for the between-group differences. The sponsor reports no meaningful additional weight loss with low-dose trevogrumab.

MRI/safety/limits: Evaluable thigh-MRI changes were −1.03 ±0.22, −0.29 ±0.12 and −0.32 ±0.13; ± values are standard errors and the release omits volume units and MRI denominators. Any adverse event was reported in 77% of pooled low-dose recipients versus 82% of controls; detailed serious-event and withdrawal counts are missing. The whole registry's 1,005 enrollment spans multiple portions and is not this analysis denominator. Body composition is not demonstrated strength, mobility or fewer falls. Earlier high-dose/garetosmab safety remains separate.

U.S./next: Investigational. A further older-adult phase 2 trial is planned, without a confirmed start/readout. The sponsor describes a Lancet paper as in press; full methods and harms remain pending.

October 1 sponsor report; primary registry.

Remaining gaps: All saved named NCT records refreshed and all pages of official overlap discovery screened (23 returned records). Search starts September 5/6 from the last full successful check, not October 6 alone. Incidental matches excluded; literature, international registries, all regulatory files and complete podcast/audio appraisal remain incomplete.; BELIEVE full withdrawal tables and HOPE-3 extension adverse-event tables remain missing. The October 7 PPMD webpage is still an invitation; a third-party transcript indicates a discussion but no original replay was appraised, so its elapsed date is not a new numerical result.

Informal-source coverage: Read October 1 original NTNPerformance repost of the COURAGE release; it supplies no independent corroboration. A BiohackingU October 7 comment calls trevogrumab phase 3, but the original sponsor/registry specify phase 2; gray-market sourcing context excluded. Revisited the September 9 Cantor enobosarm direction via third-party transcript; no actual phase 3 initiation confirmed, original audio unreviewed, stable claim remains unconfirmed without repeat alert.

Full coverage record.

Source date: October 5, 2026; WMS conference September 29–October 3. Evidence: Sponsor-reported HOPE-3 open-label extension in Duchenne muscular dystrophy.

Of 106 randomized participants, 98 entered the extension (49 per original arm); 82 had month-24 assessments. Delayed-start participants had modeled PUL 2.0 changes of −2.05 points during their placebo year and −0.49 during the following deramiocel year: difference 1.56 points (95% CI 0.47–2.64). The sponsor describes this as 76% less decline. Early-start modeled declines were −0.95 and −0.89 points in years one and two.

Limits/safety: Year two lacked randomized placebo control; models used each year’s own starting score. No alpha was allocated to extension analyses; the study was not powered for month-24 comparisons. Descriptive natural-history comparisons were unmatched. The release omits new adverse-event tables. This is upper-limb function in DMD, not healthy-adult muscle growth or GLP-1 muscle preservation.

U.S./next milestone: Investigational. PPMD webinar October 7, 2026 at 1 p.m. Eastern; FDA target November 22, 2026 is not guaranteed approval.

Original sponsor report.

Verified available: 2026-09-27; original posting date unknown. Evidence: Official conference abstract available before scheduled presentation.

The extension reports partial regain of weight, fat and visceral fat after stopping bimagrumab and/or semaglutide. NCT05616013 originally randomized 507 adults; treatment ended at week 72, imaging/labs followed to week 96 and weight/BP to week 104. In the baseline-prediabetes subset (n=129), 64.7–91.7% in bimagrumab-containing groups versus 18.8–35.7% on semaglutide alone retained HbA1c <5.7%.

Limitations: Actual abstract posting date unavailable: September 27 is verification, not publication/presentation date. Follow-up denominators, intervals and missing-data details absent. Prior switching/open-label extension and subgroup comparisons limit causal inference; no proof of lasting muscle function or diabetes remission.

Safety: LDL increases on bimagrumab monotherapy reversed below baseline after withdrawal. New adverse-event counts unavailable in the abstract.

U.S. status: Bimagrumab obesity combinations remain investigational.

Next milestone: Ken Attie presentation scheduled September 30, 2026, 15:15 CEST; seek full withdrawal tables.

EASD 2026 abstract 112; Official Lilly EASD schedule.

Source date: 2026-09-17. Evidence: Sponsor conference/development announcement.

Capricor will present HOPE-3 extension and delayed-start analyses in Duchenne muscular dystrophy. Of 106 participants originally randomized, 82 reached the 24-month timepoint: 40 originally assigned to deramiocel and 42 originally assigned to placebo. WMS runs September 29–October 3, with the oral presentation scheduled for October 3. The second year is open-label, with delayed-start and natural-history analyses.

Limitations: The notice provides no numerical 24-month effect or safety estimates. The extension does not maintain a randomized placebo comparison or establish general muscle-preservation efficacy. Earlier 12-month results are baseline evidence, not new September 17 efficacy findings.

Safety: New long-term safety tables pending.

U.S. status: Investigational. The sponsor lists an FDA target action date of November 22, 2026; this does not guarantee approval.

Next milestone: WMS, September 29–October 3, with the oral presentation on October 3. FDA target action date: November 22, 2026.

Capricor original September17 release.

Source date: 2026-09-17. Evidence: Trial registry; prospective study to follow.

A randomized study will measure whether resistance training preserves contractile thigh muscle during tirzepatide treatment. The Technical University of Munich study, NCT07777575, plans to enroll 150 adults with obesity and compare 24 weeks of resistance training with usual care. MRI endpoint assessment is blinded. The primary endpoint is change in contractile thigh muscle volume. The record was first posted on August 20 and updated on September 17; the trial is listed as recruiting.

Limitations: September 7 start is still estimated in the primary registry despite mirrors calling it actual. Muscle volume is distinct from strength and everyday function; no results available. This is a training adjunct study, not a new muscle drug.

Safety: Prospective safety data pending.

U.S. status: Approved tirzepatide is the background treatment; no new indication from registration.

Next milestone: Estimated primary/overall completion May 31, 2027, not a promised readout date.

NCT07777575 current primary registry.

Related findings:

• IVIG add-on improves early inflammatory-myopathy disease activity: TIME IS MUSCLE supports earlier IVIG add-on in a small newly diagnosed inflammatory-myopathy population.

Current position: formal trials now show that drugs can reduce loss of DXA lean mass during GLP-1 treatment. The reviewed programs remain investigational for obesity-related muscle preservation. Preserving lean tissue is promising, but does not by itself establish stronger muscles, fewer falls, or better long-term health. DXA lean mass also includes tissue other than skeletal muscle.

Bimagrumab — activin type II receptor blockade. The peer-reviewed BELIEVE trial (NCT05616013; March 2026) randomized 507 adults with obesity/overweight without diabetes. Its primary endpoint was weight change at 48 weeks; semaglutide was open-label. The high-dose combination lost 17.8 kg versus 14.2 kg with semaglutide 2.4 mg and 3.3 kg with placebo. DXA showed 92.3% of the combination's tissue loss was fat versus 71.1% with semaglutide. Most grip-strength comparisons were not significant; muscle spasms, diarrhea, acne and lipid changes warrant attention. The 72-week extension was open-label with post hoc analyses, so the larger extension headline is weaker evidence. Nature Medicine trial.

A separate bimagrumab/tirzepatide phase 2 study (NCT06643728) is active, not recruiting. The diabetes counterpart (NCT06901349) was withdrawn for strategic business reasons; that is not evidence the ongoing study failed.

Trevogrumab ± garetosmab — myostatin ± activin A blockade. The 599-person COURAGE trial (NCT06299098) reported complete 26-week results at EASD 2025. With semaglutide alone, DXA lean mass decreased 3.3 kg; adding lower/higher-dose trevogrumab reduced that loss to 1.5/1.9 kg. The triplet reduced loss to 0.9 kg and increased fat loss, but had substantially more discontinuations and two deaths. The sponsor reported no established causal association with those deaths. These are sponsor/conference results using an efficacy analysis that excludes post-discontinuation data; reported P values were not adjusted for multiple comparisons. Regeneron complete 26-week report. June 2026 presentations added body-composition analyses, not a verified new pivotal functional result. 2026 presentation list.

Apitegromab — selective inhibition of myostatin activation. EMBRAZE (NCT06445075) is now a full peer-reviewed paper (June 2026), not just a 2025 press release. It randomized 102 adults receiving tirzepatide. Among 87 completers with 24-week DXA, lean mass fell 1.6 kg with apitegromab versus 3.5 kg with placebo: 1.9 kg less loss. Fat loss was similar, 8.5 versus 8.0 kg. At eight weeks after stopping both treatments, the lean-mass difference had narrowed to 0.9 kg; exploratory physical-function results showed no notable between-group difference. Detailed safety results are summarized below; the small, mostly female sample and completer analysis limit generalization. Nature Medicine EMBRAZE report.

SRK-439 — next selective myostatin inhibitor. A phase 1 healthy-volunteer study is ongoing. It is not yet evidence of efficacy alongside GLP-1 treatment. Scholar Rock's recent emphasis is severe neuromuscular disease, and further obesity development needs to be followed explicitly. August 2026 status, company obesity partnering plans.

Enobosarm — formal oral selective androgen-receptor modulator program. Included only as Veru's regulated development program. Sponsor-reported QUALITY results in 168 adults aged at least 60 support lean-mass/function preservation with semaglutide, but were short and population-specific. The newer phase 2b PLATEAU trial enrolled 239 adults aged at least 65 with BMI at least 35; its primary outcome is incremental weight reduction, with DXA, stair-climb function, and bone density among secondary outcomes. August 2026 program update.

EMBRAZE: tirzepatide + apitegromab versus tirzepatide + placebo. Safety follow-up continued through week 40 (24 weeks of treatment plus 16 weeks off treatment), with 51 participants per arm. Any adverse event occurred in 39/51 (76%) versus 36/51 (71%); serious events in 1/51 (2%) each. Nausea was reported by 20 versus 16 participants, fatigue by 13 versus 6, and headache by 11 versus 5. Study-drug discontinuations due to adverse events were 2 versus 3; the paper does not separately enumerate each component stopped or study withdrawal. Deaths and total infusion-reaction incidence were not separately reported. Safety table, article and methods.

BELIEVE: semaglutide 2.4 mg + bimagrumab 30 mg/kg versus semaglutide 2.4 mg + bimagrumab placebo. The week-48 safety populations were 55 versus 56, distinct from 57 randomized per arm. Any adverse event occurred in 54/55 (98.2%) versus 51/56 (91.1%); serious events in 4/55 (7.3%) versus 6/56 (10.7%); adverse-event treatment discontinuations in 3/55 (5.5%) versus 5/56 (8.9%). Muscle spasms affected 63.6% versus 8.9%, acne 52.7% versus 8.9%, and diarrhea 49.1% versus 35.7%. One non-serious combination-arm episode was adjudicated as pancreatitis despite the investigator-coded row being zero. Adjusted LDL change was +11.1 ± 4.3 versus −14.0 ± 2.4 mg/dL (mean ± standard error). Safety table and footnotes, lipid results.

These are observed adverse events, not necessarily treatment-caused side effects. The small phase 2 comparisons cannot establish equal safety, a safety advantage, or rare-event risk. BELIEVE's separate weeks 48–72 extension and longer registry follow-up should not be mixed with these week-48 rates.

• Sponsor-announced: SRK-439 phase 1 topline anticipated late 2026; enobosarm PLATEAU interim DXA results Q1 2027, final topline Q4 2027. These are sponsor windows, not guaranteed dates; sources above.
• Completed regulatory action, different indication: FDA approved apitegromab for SMA on September 11, 2026, superseding the previously expected September 30 action date. Obesity-related muscle preservation remains investigational. See the focused update above. Earlier forecast retained for provenance: August regulatory status.
• No reliable public readout date verified: bimagrumab/tirzepatide efficacy or COURAGE's 52-week maintenance results. A registry completion date should not be presented as a publication deadline.

What would materially strengthen the case: replicated preservation of measured muscle, improvement in strength/function, durable benefit after withdrawal, and acceptable longer-term safety. No approval timing for obesity muscle preservation can responsibly be inferred from these phase 1/2 results.