On the first Sunday of January you put a pen in the butter compartment of the fridge. It sits between the good salted butter and a jar of capers of uncertain age. Then you open a note on your phone called The Ledger, with one column for what goes out and one for what comes back.

You are in fashionable company. Shamsah Amersi, an ob-gyn in Santa Monica, told Science News in March that about 60% of her patients over 40 now take a small dose of a GLP-1. A survey the magazine cited found about one in seven American GLP-1 users had tried microdosing. Some wanted to save money. Others wanted to age more slowly, which is harder to price and much easier to sell.

Every benefit that made these drugs famous was bought at full dose by people who were already ill. No trial has yet reported what a microdose buys a healthy woman. Keep the ledger faithfully for a year and one credit line fills with evidence, and you write that one yourself.

Open refrigerator at night with a GLP-1 injection pen in the butter compartment, a hand reaching in for it

The short answer: GLP-1 microdosing has no published human evidence as a longevity strategy. The heart and weight results behind semaglutide came from full doses in people who were already ill, and the only registered microdosing trial has posted no results. In Canada semaglutide needs a prescription, so a microdose is off-label and depends on a willing prescriber.

  • SELECT, in the New England Journal of Medicine: full-dose semaglutide cut heart attacks, strokes and cardiovascular deaths by 20% in heart patients
  • Nature, September 2026: old female mice on daily semaglutide reached a median 834 days of life, versus 742 on placebo
  • Health Canada approved the first generic semaglutide in April 2026, and CBC priced it near $100 a month by late May
The credit column Shown at full dose Shown at a microdose How sure are we
A healthier heart Fewer heart attacks and strokes Not tested Established, at full dose only
A sharper brain Two large Alzheimer's trials did not slow decline Not tested Unsupported
A longer life Never tested in people Not tested Emerging, in animals
Keeping your muscle The drug alone costs some lean mass Not tested Established for lifting and protein, at any dose

January: a lizard in the butter compartment

Semaglutide is a prescription drug in Canada, so GLP-1 microdosing is off-label and needs a willing prescriber. In April, as Health Canada approved the first generic, Global News put brand-name Ozempic at $200 to $450 a month. By late May, CBC found generic semaglutide at pharmacies for about $100.

Gila monster lizard with beaded orange and black skin resting on a red rock in the Arizona desert

At that price, an illustrative year of full pens comes to about $1,200 before fees or insurance. Stretch each pen across more weeks and the figure shrinks, which is half the appeal.

The line item has a strange pedigree. More than three decades ago, John Eng, an endocrinologist at a veterans' hospital in the Bronx, found a hormone in Gila monster venom. It behaves like our own GLP-1 and lasts for hours instead of minutes. The lizard spends most of its life underground in the Arizona desert, holding its blood sugar steady between rare meals. Anyone who has survived a Canadian February will recognize the lifestyle.

That discovery became a family of drugs built for diabetes and later obesity, and healthy women chasing longevity were never part of the design.

April: what does microdosing semaglutide actually buy?

Spring is when you start the credit column, and the first entry has a famous name. SELECT, published in the New England Journal of Medicine, is the trial behind every longevity podcast that mentions a heart. On the full weekly dose, heart attacks, strokes and cardiovascular deaths fell by 20% against placebo.

Open notebook ledger for tracking GLP-1 microdosing costs on a kitchen table with pharmacy bags, a pen and a cup of tea

Read the guest list, though. Everyone enrolled was middle-aged or older, carried extra weight and already had heart disease. Novo Nordisk, which makes the drug, paid for it. The result is real, and it belongs to them the way a stranger's winning lottery ticket belongs to the stranger.

Katy Williams, a bariatric medicine specialist at the University of Missouri, told Science News there is "no rigorous scientific data to support microdosing." A result earned at full dose by heart patients cannot be copied into a healthy woman's ledger at a fraction of the dose.

July: has anyone tested GLP-1 microdosing in a trial?

By midsummer a careful bookkeeper goes looking for receipts, and there is exactly one drawer to open. A trial registered on ClinicalTrials.gov is testing microdosed semaglutide for "health and longevity improvement". The sponsor is AgelessRx, a US telehealth company that sells longevity prescriptions, and it recruits only its own patients.

Up to 150 adults take compounded semaglutide under the tongue, by injection or as a placebo, for up to six months. The outcomes are pain scores, mood questionnaires, blood panels and wearable data. Lifespan is nowhere on the list, which is fair, since six months is a short window in which to live longer.

The estimated finish date passed last December, and the registry still shows no results. A company testing its own product on its own customers could still produce useful data one day. So far, the only receipt for a microdose is an empty envelope.

Cheaper routes add their own line in red ink. Health Canada has recalled compounded semaglutide made by an Alberta pharmacy with an unauthorized ingredient. This year it also warned Canadians off fake GLP-1s sold online.

September: a mouse makes the news

Early in the month, Nature published the headline your group chat forwarded twice. Old female mice given semaglutide every day lived a median of 834 days, against 742 on placebo. Each got a daily injection from a lab technician, a level of personal service no Canadian walk-in clinic has ever offered.

The authors are careful. Knowing whether it happens in people, they write, "will require long-term clinical studies." The year's most exciting credit was earned by a mouse, and it is written in pencil.

October to December: the column you fill yourself

The last quarter happens at 7 a.m. in a gym that smells of rubber mats and someone's eucalyptus shower gel. On full-dose semaglutide, scans show some muscle leaving with the fat. Our guide to what GLP-1s take lays out what that asks of your plate. Where trials paired these drugs with exercise, people shed more fat than on either alone.

Woman in her late thirties lifting a kettlebell overhead in a bright gym with tall arched windows

Lifting and eating enough protein is the one line in this ledger with trial evidence behind it, and it pays out at any dose, including none. The hard part is eating enough when the pen has shrunk your appetite to an espresso cup.

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In December you total the columns at the kitchen table, tea going cold beside you. The debit side runs to a year of pharmacy receipts. On the credit side sits a single line in your own handwriting, the weight on the kettlebell, and it went up.

This article is general information and does not replace advice from your doctor or pharmacist.

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Frequently asked questions

What exactly counts as a microdose?

There is no agreed definition. Cedars-Sinai obesity specialist Dr. Amanda Velazquez says "microdosing is not a medical term," and the hospital notes that some wellness companies define it arbitrarily as 25% of a standard dose. Two women who both microdose may take very different amounts.

How do I know the semaglutide I'm offered is real?

Buy only from a licensed pharmacy with a prescription, and look for the eight-digit Drug Identification Number (DIN) on the label. You can search that number in Health Canada's Drug Product Database. A product with no DIN, or one sold without a prescription, is unauthorized.

Will a small dose spare me the side effects?

Nobody has measured that. At full dose in the SELECT trial, 16.6% of people on semaglutide stopped because of adverse events, against 8.2% on placebo. Prescribers already start low and increase slowly for this reason, to limit nausea and other stomach effects.

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