How to Use THR-123
Complete guide to THR-123 dosing, administration, timing, and protocol recommendations.
Quick Overview
THR-123 is a small synthetic 16-residue cyclic peptide designed to mimic part of the protein BMP7 (bone morphogenetic protein 7) and switch on its receptor, ALK3, in the kidney. It was developed by Thrasos Therapeutics and made famous by a 2012 Nature Medicine paper showing that, taken orally, it could reverse kidney fibrosis and trigger kidney regeneration in mice. It is a preclinical research compound with no human trials of its own, though its intravenous sibling THR-184 reached Phase 2 for acute kidney injury.
Dosing Guidelines
Common Dose
2-5 mg orally per day (community starter, extrapolated from animal data)
Frequency
Once daily
Dose Range
2-10 mg per day, oral
Note: There are no human clinical trials for THR-123. Community-reported ranges so far are extrapolated from the mouse data (0.5-2 mg/kg orally daily, Nature Medicine 2012 + Nature Communications 2025) using standard FDA allometric scaling (mouse to human: divide mg/kg by 12.3). For a 70 kg adult that lands at roughly 2-10 mg orally per day. The handful of community protocols circulating start at the low end (2-5 mg/day) and titrate based on tolerance. THR-123 is unusual in that it is genuinely orally bioavailable thanks to its cyclized structure, so injection is not necessary. Cycles typically run 4-8 weeks, matching the animal model durations.
Administration Method
Oral (cyclized peptide is GI-stable, which is unusual for a peptide). Some animal studies use intraperitoneal injection.
Best Time to Take
Morning, on an empty stomach (preclinical protocols)
Oral peptides typically have better absorption on an empty stomach. Animal model protocols dosed in the morning to align with natural circadian regenerative cycles.
Protocol Duration
2-8 weeks in animal model studies; community protocols mirror this with 4-8 week cycles
Possible Side Effects
Not everyone experiences these. Individual responses vary.
- •No human safety data exists
- •No osteogenic side effects observed in animal studies (unlike full-length BMP-7)
- •Long-term safety profile unknown
- •BMP signaling has broad tissue effects; off-target signaling possible at higher doses
- •Research chemical quality and purity vary widely between suppliers
Frequently Asked Questions
What is the recommended dose for THR-123?
2-5 mg orally per day (community starter, extrapolated from animal data)
How do you administer THR-123?
Oral (cyclized peptide is GI-stable, which is unusual for a peptide). Some animal studies use intraperitoneal injection.
When is the best time to take THR-123?
Morning, on an empty stomach (preclinical protocols)
How long should you use THR-123?
2-8 weeks in animal model studies; community protocols mirror this with 4-8 week cycles
This information is for educational purposes only. Always consult with a healthcare professional before using any peptide. Dosing information is based on research literature and community reports, not medical advice.