The Core Difference: Ester vs No Ester
RAD-140 (Testolone) and RAD-150 (TLB-150) are structurally very similar. The primary difference is that RAD-150 has a benzoate ester group attached, which extends its half-life significantly. In research models, the ester is cleaved to release RAD-140 as the active compound — meaning both compounds ultimately act through the same mechanism.
⚠ Research Purposes Only: Both RAD-140 and RAD-150 are research chemicals not approved for human consumption by the FDA or MHRA.
Head-to-Head Research Comparison
| Factor | RAD-140 | RAD-150 |
|---|---|---|
| Half-Life | 15–20 hours | ~48+ hours (estimated) |
| Human Trial Data | Phase I published (2020) | Preclinical only |
| Active Compound | RAD-140 directly | Cleaved to RAD-140 |
| Onset Speed | Faster | Slower (ester delay) |
| Research Volume | High | Low–Moderate |
| Primary Advantage | More clinical data | Longer half-life |
Which Has More Research Support?
RAD-140 is the clear winner in terms of published research volume. It has a completed Phase I human clinical trial (Miller et al., 2020 — NCT02239016) in postmenopausal women with hormone receptor-positive breast cancer, as well as earlier trials examining safety and pharmacokinetics.
RAD-150 is considerably newer with very limited published human data. Researchers choosing between the two for a protocol where clinical data is a priority should note that RAD-140 is substantially better documented.
Suppression Comparison
Both compounds are expected to suppress the HPTA. Due to RAD-150's longer half-life, suppression may take longer to resolve after discontinuation. This is an important consideration for research protocols that include hormonal recovery measurement.
Verdict for USA & UK Researchers
If the research priority is a well-documented compound with human clinical data: RAD-140. If the protocol specifically requires a longer half-life esterified SARM: RAD-150. Both are available from verified US and UK vendors with third-party testing.
🔬 Where to Source RAD-150 & RAD-140 for Research (USA & UK)
For USA and UK researchers, SwissChems is one of the most reliable sources with third-party certificates of analysis. All products are for research purposes only and not approved for human consumption.
Visit SwissChems →⚠ Affiliate link — use code Tomjunkie for 20% off. Research purposes only.
Frequently Asked Questions
RAD-150 converts to RAD-140 in research models — they share the same active compound. The primary difference is half-life, not potency. Both are research chemicals only.
RAD-140 has significantly more published human clinical data, including a completed Phase I trial. RAD-150 has primarily preclinical research available.
BehemothLabz stocks RAD-140 and SwissChems stocks RAD-150, both with third-party CoA documentation. For research purposes only.
Yes. Both compounds are expected to suppress the HPTA. RAD-150's longer half-life may result in a longer suppression window post-discontinuation.