The Longevity Desk
Comparisons

LGD-4033 vs MK-2866

There is no winner on this page. What is set side by side is the published record behind each one, which is the part the two are rarely compared on.

Both in SARMs

Both circulate above what was studied, and only one has a phase 3 record to be above. MK-2866's two phase 3 trials each carried two co-primary endpoints, a body scan and a stair climb: at day 84 the scan showed more responders on the drug in both, the stair climb showed a smaller gap in the first and went the wrong way in the second, and those registry records post no statistical test of any kind. LGD-4033's trials topped out at 1.0 mg over 21 days and 2.0 mg over 12 weeks, while the guide page carrying its 10 to 15 mg figures tells readers clinical trials support up to 222 mg a day; that page's citation list has two entries.

This is not a protocol and neither column is a recommendation. The studied row is what a trial administered to people under supervision. The circulating row is what gets reported in practice, recorded because it is what happens. Where a row is empty it is because nothing has been published, which is a fact about the literature rather than about the compound.
FieldLGD-4033MK-2866
What a trial gave1.0 mg a day for 21 days, and 2.0 mg a day for 12 weeksA phase 1 in 76 healthy men and a phase 2 in 108 hip fracture patients3 mg a day for 147 days in the phase 3 trialsTwo completed phase 3 trials in people starting chemotherapy
What circulates10 mg a day for men over 8 to 10 weeks, up to 15 for experienced users10 to 25 mg a day, reported as the commonest range on guide pages
The gapAbove the studied doseAbove the studied dose
How long it lastsI could not find a published human half life in the material behind the class page. The dosing in both trials was once daily.I could not find a published human half life in the material behind the class page. Dosing in every trial was once daily.
Route studiedBy mouth, once a day. The phase 1 randomised 76 healthy men aged 21 to 50 to a dummy or to 0.1, 0.3 or 1.0 mg for 21 days. The phase 2 randomised 108 people aged 65 and over to a dummy or to 0.5, 1.0 or 2.0 mg for 12 weeks.By mouth, once daily. The two phase 3 trials gave 3 mg a day for 147 days. An earlier phase 2 randomised 120 healthy elderly men and postmenopausal women across five arms at 0.1, 0.3, 1 and 3 mg and placebo for 12 weeks. Later trials in breast cancer used 9 mg and 18 mg.
Route usedBy mouth, at 10 mg a day for men over an 8 to 10 week cycle and up to 15 mg for experienced users, reported as convention and not as a recommendation.By mouth, at 10 to 25 mg a day, reported as the commonest range on guide pages and not as a recommendation.
Vial sizesNo vial size named in the entryNo vial size named in the entry

The distance, stated

Above the studied dose

LGD-4033

Five to fifteen times the top dose of either trial. The 21 day phase 1 randomised 76 healthy men to a dummy or to 0.1, 0.3 or 1.0 mg, and the 12 week phase 2 in people recovering from a hip fracture topped out at 2.0 mg. The guide page carrying the 10 to 15 mg figures also tells readers that clinical trials support up to 222 mg a day for 14 days; its citation list has two entries, and the only trial among them is the 21 day study whose highest dose was 1.0 mg. The one published case report that gives a daily amount describes severe liver injury at 10 mg.

Above the studied dose

MK-2866

Three to eight times the phase 3 dose, and the trials are worth reading before the dose. Both carried two co-primary endpoints, a body scan measure and a stair climb measure, both scored as responder counts on advice the design paper attributes to the American regulator. At day 84 the scan showed more responders on the drug in both trials. The stair climb showed a smaller gap in the same direction in the first and went the wrong way in the second. Those registry records post percentages and confidence intervals and no statistical test of any kind, so nothing sourced to them says an endpoint passed.

What people get wrong

LGD-4033

The trial doses and the market doses are not the same order of magnitude, and one guide page bridges the gap with a sentence that does not survive checking: it tells readers clinical trials support up to 222 mg a day for 14 days. Its citation list has two entries, and the only trial among them is the 21 day study whose highest dose was 1.0 mg.

MK-2866

The scan moved further than the person did, and that is the finding worth carrying away. Both phase 3 trials scored two co-primary endpoints as responder counts. At day 84 the body scan measure showed more responders on the drug in both. The stair climb measure showed a smaller gap in the same direction in the first trial and went the wrong way in the second. Those registry records post no statistical test at all, so nothing sourced to them says an endpoint passed either way. The one trial where a functional measure did improve against placebo was the 120 person phase 2, at 3 mg.

Every figure above is carried across from each compound’s entry, which is where the citations live.

All 65 compounds on one page at what circulates vs what was studied, or pick another two to compare.