EXPLORE THE SCIENCE.
Explore individual published studies for each compound: research design, findings, limitations and direct scientific references. Evidence, not endorsement.
Research profiles
Retatrutide
An investigational molecule acting at three metabolic hormone receptors. Human clinical studies have examined changes in body weight and metabolic outcomes.
Evidence: human randomised trialVIEW 2 PUBLISHED STUDIES & FINDINGS
Published studies (2)
Study design / model: 338 adults; double-blind, randomised, placebo-controlled; 48-week study.
What researchers reported: At 48 weeks, average weight change in the 12 mg trial arm was −24.2%, compared with −2.1% for placebo. Gastrointestinal adverse effects were commonly reported, especially during dose escalation.
What this does not establish: Phase 2 trial in a selected clinical population. Results cannot be applied to retail research materials, which were not tested in the trial.
Read the published study ↗Study design / model: Randomised, double-blind, placebo- and active-controlled phase 2 trial in adults with type 2 diabetes.
What researchers reported: Investigators examined changes in HbA1c, body weight and safety, reporting metabolic effects that supported further clinical investigation.
What this does not establish: Different patient population and endpoints from the obesity trial; not evidence for unsupervised personal use.
Read the published study ↗Mechanism under investigation
Retatrutide activates GIP, GLP-1 and glucagon receptors. The combined mechanism is being studied for metabolic effects.
What was observed
A 2023 phase 2 randomised, placebo-controlled study of 338 adults reported substantial differences in average weight change across treatment and placebo groups over 48 weeks. Results apply to the studied trial setting, not to independently sourced research materials.
What remains uncertain
Longer-term outcomes, safety in broader populations and the relevance of results outside controlled trials require careful assessment. Investigational status should not be confused with regulatory approval.
Primary source
Jastreboff et al., New England Journal of Medicine (2023) — clinical trial ↗BPC-157
A synthetic peptide widely discussed in experimental tissue-repair research. Most of the literature is preclinical.
Evidence: mainly animal studies; very limited human dataVIEW 2 PUBLISHED STUDIES & FINDINGS
Published studies (2)
Study design / model: Retrospective chart review; 17 records, 16 patients reached for follow-up; some received BPC-157 alone and others received BPC-157 plus thymosin β4.
What researchers reported: 14 of 16 contacted participants reported pain relief, including 11 of 12 reporting improvement in the BPC-157-only subgroup.
What this does not establish: No randomisation, no placebo group, no validated functional outcome measures, and mixed interventions. Self-reported changes cannot establish efficacy or safety.
Read the published study ↗Study design / model: Systematic review of three small human studies, totalling 30 participants.
What researchers reported: The reviewers assessed all included studies as poor quality and judged the overall certainty of evidence very low.
What this does not establish: A review is a synthesis, not a new intervention trial. Authors concluded that regulated clinical trials are necessary before human clinical use.
Read the published study ↗Research focus
Animal studies have investigated responses involving tendon, ligament, muscle and inflammatory pathways. Laboratory findings should not be interpreted as demonstrated benefits in humans.
What the human evidence says
A 2026 systematic review identified three small human studies totalling 30 participants, all assessed as poor methodological quality. Overall certainty of evidence was judged very low.
Open questions
Reliable clinical effectiveness, appropriate safety evaluation and longer-term human outcomes remain unestablished.
Research source
Poolton et al., Acta Orthopaedica Belgica (2026) — systematic review ↗MOTS-c
A mitochondria-derived peptide studied for its role in cellular signalling and energy metabolism.
Evidence: cellular and animal researchVIEW 1 PUBLISHED STUDY & FINDINGS
Published studies (1)
Study design / model: Laboratory experiments and mouse models examining mitochondrial peptide signalling and metabolism.
What researchers reported: The study linked MOTS-c to metabolic signalling involving AMPK and reported effects on insulin resistance and weight-related outcomes in mice.
What this does not establish: No demonstration of clinical effectiveness or safety from administered MOTS-c in humans.
Read the published study ↗Biological interest
MOTS-c is encoded within mitochondrial DNA. Experimental work connects it with cellular metabolic signalling, including AMPK-associated pathways.
What studies found
A foundational 2015 paper reported metabolic effects in mouse experiments and explored the mechanisms in cells.
Limitations
Findings in mice cannot establish efficacy or safety of administered MOTS-c in people. The evidence should remain clearly labelled as preclinical.
Primary source
Lee et al., Cell Metabolism (2015) — preclinical study ↗Tesamorelin
A growth-hormone-releasing hormone analogue with clinical trials in a specific population of adults living with HIV.
Evidence: controlled human clinical trials for a specific indicationVIEW 2 PUBLISHED STUDIES & FINDINGS
Published studies (2)
Study design / model: 404 adults with HIV and excess abdominal fat; randomised placebo-controlled efficacy phase over six months, followed by extension.
What researchers reported: Average visceral adipose tissue changed −10.9% in the trial treatment group versus −0.6% with placebo after six months.
What this does not establish: Specific clinical population and medically supervised protocol; does not establish general fitness or anti-ageing effects.
Read the published study ↗Study design / model: Randomised controlled study in adults with HIV and abdominal fat accumulation.
What researchers reported: Researchers investigated visceral adipose tissue and liver-fat outcomes, reporting reductions compared with placebo in this clinical setting.
What this does not establish: Findings relate to a studied medical indication and cannot be extrapolated to unregulated research materials or other populations.
Read the published study ↗Mechanism
Tesamorelin is a GHRH analogue that stimulates the growth-hormone axis.
What was studied
Randomised trials in adults with HIV-associated abdominal fat accumulation reported reductions in visceral adipose tissue compared with placebo. These findings are specific to the population and clinical indication investigated.
Limits of extrapolation
Evidence for a defined medical indication does not demonstrate general-purpose fat-loss, physique or anti-ageing benefits in otherwise healthy populations. Clinical product approvals do not extend to unrelated research vials.
Primary sources
Falutz et al. (2010) — randomised controlled trial ↗Stanley et al., JAMA (2014) — randomised clinical trial ↗TB-500 & Thymosin β4
An important research distinction: products described as TB-500 are not necessarily identical to full-length thymosin beta-4 used in published studies.
Evidence: compound-specific human data insufficientVIEW 2 PUBLISHED STUDIES & FINDINGS
Published studies (2)
Study design / model: Small placebo-controlled trial involving nine patients and a formulated thymosin β4 ophthalmic investigational product (RGN-259).
What researchers reported: Researchers reported improvements on selected ocular sign and symptom measures at certain assessment points.
What this does not establish: This was FULL-LENGTH thymosin β4 in an eye-drop formulation, not TB-500. These results do not establish effects of TB-500 fragments or products bearing that name.
Read the published study ↗Study design / model: Review of laboratory, animal and human literature, alongside product identity and safety questions.
What researchers reported: Reviewers highlighted substantial gaps in controlled clinical evidence and the need to distinguish TB-500-labelled products from full-length thymosin β4.
What this does not establish: Review article, not a direct TB-500 efficacy trial. There is no established interchangeability between these molecules.
Read the published study ↗What researchers investigate
Thymosin beta-4 and related peptide fragments have appeared in cell and animal investigations of tissue responses and repair pathways.
Why identity matters
Evidence relating to full-length thymosin beta-4 cannot simply be transferred to a shorter fragment or to a product sold under the TB-500 label.
Major gaps
Human safety and effectiveness evidence for material marketed as TB-500 remains inadequate. Precise molecular identity and study conditions must be checked before drawing conclusions.
Research source
Investigational Peptides in Orthopaedic Practice (2026) — narrative review ↗Not all evidence is equal.
Cell experiments explore mechanisms in controlled laboratory systems. Animal studies may help researchers form hypotheses. Human trials test particular interventions in particular populations. Even a positive human trial does not establish that an unrelated product is equivalent, approved, or suitable for use.