Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Mirabegron (YM-178) and Sobetirome (GC-1) — mechanism, side effects, legal status, and pricing.
Mirabegron is a non-peptide, small-molecule selective β3-adrenergic receptor agonist FDA-approved in 2012 for overactive bladder at 25–50 mg/day oral dosing. It is also sold as unregulated 'research use only' powder by fine-chemical vendors, despite being a prescription pharmaceutical. Investigational metabolic research has used a supratherapeutic 100 mg/day dose to study brown adipose tissue activation—an off-label, non-approved use. Mirabegron is pharmacologically distinct from WADA-prohibited β2-agonists, though its it is not on the WADA Prohibited List (only beta-2 agonists are prohibited, Category S3).
Sobetirome (GC-1) is a non-peptide small-molecule thyromimetic that selectively activates thyroid hormone receptor beta (TRβ) over TRα, designed to lower cholesterol and triglycerides without the cardiac effects of natural thyroid hormone. It completed Phase 1 trials in healthy volunteers for dyslipidemia (discontinued), but has no FDA or EMA approval and no validated human dose for any indication. Planned human trials in X-linked adrenoleukodystrophy were withdrawn before enrollment; all neurological data are preclinical only.
Mirabegron (YM-178)
Sobetirome (GC-1)
Category
Legal Status
Mechanism
Side Effects
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Mirabegron (YM-178)
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Check Mirabegron (YM-178) prices →Sobetirome (GC-1)
COA corpus from Disclosed Labs — independently tested batches only.
Mirabegron (YM-178)
1
COAs
99.8%
Avg purity
1
Labs
Sobetirome (GC-1)
1
COAs
97.3%
Avg purity
1
Labs
Mirabegron is an FDA-approved drug with extensive human data, not a novel research chemical. Approved adult dosing is 25 mg once daily, increased to 50 mg after 4–8 weeks for overactive bladder. A registered clinical trial (NCT04823442) used 100 mg/day for 4 weeks in 14 healthy women, reporting increased brown adipose tissue activity/volume, HDL cholesterol, insulin sensitivity, and resting energy expenditure with no change in body weight or fat mass (O'Mara et al., J Clin Invest 2020, PMID 31961826)—an open-label study without placebo control. Rat studies confirmed selective β3-adrenoceptor agonist activity with bladder-relaxant effects (Hatanaka et al., 2013, PMID 23239087). Ex vivo porcine ureter studies found mirabegron reduced contractility partly via α1-adrenoceptor antagonism, complicating a pure β3-selectivity profile at the ureter (PMC9192402).
Human data are limited to Phase 1 trials in healthy volunteers conducted by QuatRx Pharmaceuticals; company press releases (not peer-reviewed) reported LDL-C reductions up to 22% (single-ascending-dose, 1–450 mcg) and 41% (multiple-ascending-dose, 10–100 mcg/day × 14 days) with no significant heart-rate or TSH change. Development for dyslipidemia was discontinued and no Phase 2/3 data exist. Two planned human trials in X-linked adrenoleukodystrophy (NCT01787578, NCT03196765) were withdrawn before enrolling any participants; zero human neurological efficacy data exist. In Abcd1 knockout mice (X-ALD model), intraperitoneal dosing (0.1–1.0 mg/kg/day, 7–28 days) lowered serum and tissue very-long-chain fatty acid (VLCFA) levels; chronic oral dosing (0.4–2.0 mg/kg, 11–18 weeks) modestly reduced brain C26 VLCFA by 13–24% after 12 weeks, though the higher dose caused up to 20% body-weight loss requiring early termination. In experimental autoimmune encephalomyelitis mice, sobetirome reduced clinical disease severity, axonal degeneration, and oligodendrocyte loss versus vehicle controls.
Mirabegron (YM-178) and Sobetirome (GC-1) are both in the Metabolic category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
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