The RetaBone body-composition research agenda

RetaBone™ is not a separate formulation. It is the body-composition and metabolic-resilience identity of Rethiamine™, Panacea Bio Chem’s proprietary dual-layer Peptourbillon™ containing a 5 mg retatrutide lower layer and a 20 mg thiamine upper layer within Lyoprester SS™, reconstituted by 0.5 mL P-EARLs™.

The scientific territory of this site is what happens around a powerful weight-reduction pharmacology: how much of the lost weight is fat and how much is lean tissue; what DXA actually measures; how nutritional intake, protein, resistance exercise and micronutrient status behave when appetite is pharmacologically suppressed; and what is and is not known about bone. The RetaBone name does not mean that the formulation has been demonstrated to increase bone density, prevent fractures or preserve skeletal muscle. These remain separate scientific questions requiring dedicated study.

RetaBone explores whether thiamine integration may contribute to a more nutritionally considered retatrutide formulation architecture. It does not claim that thiamine builds bone, prevents muscle loss, or replaces adequate protein intake and resistance training. Every claim on this site carries its evidence tier, its limitations and its source.

The anchor dataset is Coskun and colleagues (Lancet Diabetes & Endocrinology 2025), the only retatrutide DXA body-composition substudy published to date: total fat mass fell up to 26.1% at week 36 in people with type 2 diabetes, with the authors reporting the lean-mass share of weight loss as similar to other obesity treatments. The caveats matter: 103 of 189 substudy participants completed both DXA scans, the population had type 2 diabetes, and neither muscle function nor bone outcomes were measured.

The class benchmarks frame the reading. In the SURMOUNT-1 DXA substudy (Look 2025, n=160), tirzepatide produced −33.9% fat mass and −10.9% lean mass at week 72 — roughly 75% of weight lost as fat and 25% as lean mass, a split also seen in the placebo arm’s smaller losses. The 35-trial systematic review by Batsis and colleagues (Annals of Internal Medicine 2026) found a median ~28.3% of weight lost on incretin therapies attributable to muscle-based indices — and, just as important, no included study reported objective physical-function outcomes. SEMALEAN (Alissou 2026) added rare functional data for semaglutide: lean-mass decline that stabilised after month 7 with improved handgrip strength, in an uncontrolled single-arm design.

One methodological caveat governs every figure above: DXA lean mass is not synonymous with skeletal muscle. As Prado and Heymsfield (2014) set out, DXA lean soft tissue includes water and other non-muscle lean tissues, which CT or MRI can distinguish. Retatrutide body-composition research indicates that fat mass decreases substantially, while some lean-mass reduction may also occur. The proportion should not be exaggerated into 'muscle destruction,' because DXA lean mass also includes water and non-muscle lean tissue.

The external evidence base supplies the concern, not the answer. The 2026 EASO/EFAD/ECPO consensus statement on incretin-based therapies calls for protein targets, resistance exercise and explicit micronutrient-risk monitoring during rapid weight loss. Scoping and narrative reviews document sarcopenia and sarcopenic-obesity risk, and note that total weight alone cannot distinguish fat, lean tissue, water and bone. None of these publications establishes that retatrutide directly depletes thiamine — direct retatrutide-induced biochemical depletion of thiamine has not been established.

The Panacea hypothesis is narrower than the concern: potent appetite suppression, reduced dietary intake, gastrointestinal intolerance and rapid weight reduction may create nutritional vulnerability in some individuals, and integrating thiamine into a once-weekly retatrutide formulation could provide a more coherent pharmaceutical research architecture. Thiamine participates in energy-producing biochemical pathways and nervous-system function; humans maintain limited thiamine reserves. Whether a weekly 20 mg thiamine component can meaningfully support thiamine status is a question for measurement, not assumption.

This hypothesis carries explicit boundaries. It does not claim that thiamine builds bone, prevents retatrutide-associated muscle loss, or replaces adequate protein intake and resistance training. It does not claim sustained seven-day thiamine release. It is testable — through measurements of thiamine status, formulation stability, and pharmacokinetic evaluation — and it stands or falls on that measurement.