Why is one semaglutide trial at 609 and another only 62?

2026-08-20 9632 views 51 posts

I've been watching semaglutide trial listings since January. NCT06897475 is recruiting with 200 enrolled, NCT06989203 is recruiting with 140, and NCT07401992 is recruiting but only 62.

The completed NCT02079870 had 30. Then NCT07011667 is active, not recruiting with 609. Why such a spread?

Is it phase, population, or endpoint?

I'm not enrolled in any of them, just trying to read enrollment numbers as a signal. Am I overthinking, or do these gaps actually mean something?

Small n doesn't always mean early. Could be a narrow inclusion window. The 609 one is the only one I'd call a real cohort.

Agree on narrow window. 62 makes me think imaging or PK substudy, not standard.

Wait, NCT07011667 already has 609? That's the one I'd watch if they post data.

I'd rather see 200 in NCT06897475 than 609 in something with no posted results. Enrollment size isn't quality.

The 30-person completed NCT02079870 is the weird one for me. Tiny, but at least it's done.

Completed doesn't mean useful. If it was 30 people, I wouldn't weigh it much against the recruiting ones.

I've been in a different trial, not semaglutide, and our enrollment looked huge because it was multisite. The number alone didn't tell me much about dose or endpoint. What I'd want here is phase, oral vs injectable, and duration. NCT07401992 at 62 could still be a focused PK/PD study.

NCT06897475 at 200 sounds more like a typical phase 2/3 size, but without listing details it's guessing.

Oral vs injectable is the real split in these threads. Oral posts get buried under injection talk — you have to scroll through pages of needle chat just to find anyone comparing the two.

Same. I check trial listings because the forums mostly repeat the same starter side-effect stuff.

So maybe it's: 609 = big registry, 200/140 = mid, 62 = niche. Not rocket science, but it tracks.

609 looks huge until you divide it by site count — that one's spread across something like 60 locations, so it's roughly 8-10 people per site, while the 62-person study might be four sites doing heavy screening. Counterintuitive, but the bigger headline number is often harder to get into locally.

I've kept a weight spreadsheet since January, 41 weekly entries, and I do the same math with listings: per-site slots tell you whether it's worth a phone call, not the total.

Phase and design do most of the work here. A 30-person completed study screams phase 1 or a small PK thing, while 609 is phase 3 where you need bodies for subgroup power and rare-event capture.

Also check the "estimated" flag on those listings — plenty never get updated after they stop recruiting, so a stale 62 could really be 40 or 90. What flipped it for me: I chased a 200-slot listing last spring assuming I'd breeze in, got told 190 spots were already filled and the page lagged a month.

Now I sort by last-updated date, not enrollment size.

Same reason I weigh myself at the same time every morning — a number is only useful if it's current.

Population and eligibility matter as much as phase. A study in people with type 2 diabetes versus one in obesity without diabetes versus one in kidney or liver stuff pulls from completely different screening pools, so enrollment reflects how many they think they can actually find, not how promising the drug is.

Endpoint counts too — a long weight-focused study needs way more people than a short tolerability one. My own data point: I've got 14 months of waist measurements at the navel, and my waist dropped 4 inches before the scale moved 8 pounds, which is exactly why some of these track waist or visceral fat instead of just pounds.

Enrollment is a recruitment budget, not a quality score.

Honestly the spread bugged me less once I noticed the dates — that completed 30-person one is from over a decade ago, way before anyone was running giant obesity trials, so stacking it against a current listing is apples to oranges. Different era, different recruitment budgets.

Contrarian take: enrollment size tells you almost nothing about whether a study is worth your time.

A tight 62-person study with frequent visits can be more informative than 609 people mostly filling out surveys. Sharper read: look at the primary outcome and how many in-person visits it wants, because that predicts who finishes.

I watched my own 12-week gym streak die at week 9 purely because the commute was 40 minutes.

Site count is the boring thing nobody mentions. A 600-person study usually means 15-20 clinics each pulling 30-40 people, while a 62-person one is often one or two sites with a narrow window.

I was in a non-GLP study years ago at a single site and they closed enrollment in five weeks. Same condition, similar endpoint, wildly different n. Worth asking how many sites and how long the window stayed open.

Small n isn't automatically weaker, it just answers a narrower question. 62 people with frequent labs tells you plenty about short-term tolerability and almost nothing about something that hits 1 in 2,000. The 600-person one buys you rare-event signal.

I quit reading enrollment like a quality score after I found two studies with near-identical setups and a tenfold difference in n.

The trial numbers stopped mattering to me once I started tracking my own trend instead of theirs. I weigh daily but only judge the 7-day average, and I measure my waist at the same spot every Sunday morning.

218 down to 191 since January, waist down a bit over 3 inches, and there were two separate weeks the scale jumped 2 pounds for no reason I could name. Sleep and stress, probably.

Careful reading those as completers though. A 609-person trial might wrap with 480; a 30-person completed one finished with 30 because it started with 30. That makes the spread look wider than it actually is.

What are you really trying to figure out, whether a certain kind of person got studied, or whether the result would likely hold for you? Those need completely different numbers.

Half the time it's just site count. One clinic with a slow IRB can tank the whole target.