What Is a Microdose of Semaglutide? (The Actual Numbers)

If you want a number for "what is a microdose of semaglutide," here it is up front, with the honest caveat attached: there is no official microdose of semaglutide. No agency, no manufacturer, and no clinical trial has ever defined one. But the term is used fairly consistently online, so we can describe the range people actually mean, show exactly where it sits below the real approved doses, and be straight about what that number does and doesn't get you.

The short answer: below the 0.25 mg starting dose

When people say "microdose of semaglutide," they mean a weekly dose below the 0.25 mg starting dose — typically a fraction of it. The amounts that circulate in microdosing communities and on telehealth menus usually land somewhere around 0.05 mg to 0.2 mg once weekly, with some going lower. There's no agreed cutoff, so two people "microdosing semaglutide" may be taking quite different amounts. Microdose sounds like a precise unit; for semaglutide, it isn't.

To see why that's the range, you need the real dose ladder it sits beneath.

What the approved doses actually are

Semaglutide is the active drug in Ozempic and Rybelsus (type 2 diabetes) and Wegovy (weight management). For weight, the Wegovy label initiates at 0.25 mg once weekly for four weeks, then titrates upward — 0.5, 1, 1.7 — to a maintenance dose of 2.4 mg once weekly, and the label is explicit that 0.25 mg is a tolerability starter to be escalated, not a maintenance dose meant to deliver the full effect¹. That target of 2.4 mg is the dose that produced the headline trial results.

So the reference point matters: even the lowest official rung (0.25 mg) is a warm-up, not a therapeutic target. A microdose sits below that warm-up — which is the single most useful thing to grasp about the number.

So what counts as a microdose, concretely?

A working definition of a semaglutide microdose: a deliberately chosen weekly dose below 0.25 mg — most commonly around 0.05–0.2 mg, sometimes lower — held there on purpose rather than as a step toward 2.4 mg. Three features define it:

• •Below the starting rung. It's under the 0.25 mg the label uses only to build tolerance¹.
• •Self-selected, not validated. The exact amount comes from the user, a compounding pharmacy, or a telehealth service — not a dose-finding trial. No trial has tested an intentional microdose.
• •Usually compounded. Approved pens aren't sold in microdose strengths, so a microdose almost always means a compounded vial drawn up by hand. We cover that math in how to reconstitute and measure a compounded GLP-1 microdose.

For the side-by-side numbers, see the GLP-1 microdosing chart.

How semaglutide works — and why dose size matters

Semaglutide is a GLP-1 receptor agonist. It enhances glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite through central pathways². That biology isn't in dispute. But the effects are exposure-dependent: you need enough drug present to occupy enough receptors to actually shift appetite and metabolism. "The receptor is activated" is not the same as "activated enough to do what the trials showed." A microdose, by its own definition, sits at the bottom of that exposure range.

What that number probably buys you — and we can be unusually specific here

Semaglutide is the rare case where the dose-response curve was actually mapped, so we can be concrete. A phase 2 dose-ranging trial measured weight loss across doses, and it scaled cleanly³:

• •0.05 mg: about −6.0%
• •0.1 mg: about −8.6%
• •0.2 mg: about −11.6%
• •0.4 mg: about −13.8%

And the approved full dose sits at the top: semaglutide 2.4 mg produced about 14.9% mean weight loss in STEP 1⁴. Read the curve from the bottom: the lowest dose tested produced the smallest effect, and the effect grew with dose. The microdose range (~0.05–0.2 mg) overlaps the bottom of that curve — so the honest expectation is a real but smaller effect, not a discounted version of the 15% headline. Note too that those phase 2 doses were tested as a managed trial, not as a "hold it tiny forever" strategy. We unpack the full curve in GLP-1 dose-response: why lower doses do less.

"Smaller dose" is not "officially safer"

It's tempting to read "microdose" as automatically gentler and safer. A lower dose may soften some dose-related side effects, but it doesn't make the drug class risk-free — GLP-1 agonists used for weight loss have been linked in a large real-world analysis to elevated risk of pancreatitis, bowel obstruction, and gastroparesis⁵. And because a microdose is almost always compounded and measured by hand, it carries its own hazards: a pharmacovigilance analysis of compounded GLP-1 agonists found markedly elevated reporting for preparation errors, contamination, and dosing mistakes⁶, and the only clinical literature specifically on microdosing is cautionary, warning about dosing errors and unregulated sourcing⁷. A small number doesn't make the practice low-risk. See is compounded / microdosed GLP-1 safe?.

There's also a staying-power catch. The benefit tracks ongoing exposure: in STEP 4, people who stopped semaglutide regained weight while those who continued held their loss⁸. A dose small enough to be a "microdose" may be below the threshold needed to hold a meaningful effect.

The bottom line

A microdose of semaglutide isn't an official dose — it's a self-selected weekly amount below the 0.25 mg starting rung, most often around 0.05–0.2 mg, held there on purpose. It's off-label, almost always compounded, and untested as an intentional strategy. The mapped dose-response curve says lower doses do less, the proven 15% result came from the full 2.4 mg dose, and "smaller" isn't the same as "safer." Treat the number as an unproven extrapolation and decide with a qualified clinician.

For the bigger picture, start with the pillar microdosing GLP-1: what the evidence actually shows and the deeper companion microdosing semaglutide: does a sub-therapeutic dose do anything?, and for the tirzepatide equivalent, what is a microdose of tirzepatide?. To compare providers on price and oversight, see our GLP-1 microdose rankings hub.