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 Sobetirome (GC-1) — 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.
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 Planned human trials in X-linked adrenoleukodystrophy were withdrawn before enrollment; all neurological data are preclinical only.
3,5-Diiodo-L-thyronine (3,5-T2)
Sobetirome (GC-1)
Category
Legal Status
Mechanism
Side Effects
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3,5-Diiodo-L-thyronine (3,5-T2)
No pricing data yet.
Check 3,5-Diiodo-L-thyronine (3,5-T2) prices →Sobetirome (GC-1)
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
Sobetirome (GC-1)
1
COAs
97.3%
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
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.
3,5-Diiodo-L-thyronine (3,5-T2) 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.
Contraindications
Lab Testing
Key references
Disclosed Labs