Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of 3,5-Diiodo-L-thyronine (3,5-T2) and Mirabegron (YM-178) — mechanism, side effects, legal status, and pricing.
3,5-Diiodo-L-thyronine (3,5-T2) is a non-peptide endogenous iodothyronine produced by deiodination of T3 and T4. It is not an approved drug and has no registered human clinical trials as a study intervention. The only direct human-administration data come from a single 2-person case report. WADA/anti-doping status for 3,5-T2 specifically is unconfirmed; a 2019 secondary source suggested thyroid hormones as a class were not prohibited, but no current primary WADA citation was found.
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).
3,5-Diiodo-L-thyronine (3,5-T2)
Mirabegron (YM-178)
Category
Legal Status
Mechanism
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
3,5-Diiodo-L-thyronine (3,5-T2)
No pricing data yet.
Check 3,5-Diiodo-L-thyronine (3,5-T2) prices →Mirabegron (YM-178)
No pricing data yet.
Check Mirabegron (YM-178) prices →COA corpus from Disclosed Labs — independently tested batches only.
3,5-Diiodo-L-thyronine (3,5-T2)
2
COAs
97.4%
Avg purity
2
Labs
Mirabegron (YM-178)
1
COAs
99.8%
Avg purity
1
Labs
No approved human drug or registered interventional clinical trial exists. The only direct human-administration data are from a single 2-person case report: oral 3,5-T2 (~5 μg/kg body weight) for 28 days reportedly raised resting metabolic rate by ~15% and lowered body weight by ~4 kg, with no significant changes in principal clinical parameters and no observed side effects. Endogenous 3,5-T2 has been measured in healthy human serum (~0.22–0.33 nM) and as a metabolite in liothyronine (T3) pharmacokinetic trials. Preclinical rodent studies show 3,5-T2 rapidly increases resting metabolic rate (faster than T3), reduces adiposity in high-fat-diet models by increasing fat oxidation, stimulates liver and skeletal muscle mitochondrial bioenergetics, and activates AMPK in skeletal muscle. One rat regimen (25 μg/100g BW, 4 weeks) showed no HPT-axis suppression or cardiac hypertrophy at that specific dose/duration; however, one mouse model (unsaturated-fat diet) showed no improvement in NAFLD or insulin sensitivity.
Key references
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).
3,5-Diiodo-L-thyronine (3,5-T2) and Mirabegron (YM-178) 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.
Contraindications
Lab Testing
Disclosed Labs