Microdosing semaglutide and tirzepatide spreads as doctors say evidence is missing

Microdosing GLP-1 drugs has moved well beyond online forums. A Los Angeles Times report published June 23 finds that low-dose use of semaglutide and tirzepatide is now common enough to show up in the patient counts of a working obesity practice ^[1].

Dr. Sara Siavoshi, a board-certified obesity, neurology and headache specialist who treats about 5,000 patients, estimates that 30 to 40 percent of them are microdosing either tirzepatide or semaglutide ^[1]. Semaglutide is sold as Ozempic and Wegovy; tirzepatide is sold as Mounjaro and Zepbound ^[1]. Most of these products are self-injected weekly ^[1].

Siavoshi defines a microdose as "the lowest dose of a GLP-1 that lowers food noise without causing any significant weight loss" ^[1]. Food noise, a term used in obesity medicine, refers to chronic unwanted thoughts that make healthful choices about how much and what to eat difficult ^[1]. If a dose leads to more weight loss than 3 or 4 pounds, she says, she does not consider it a microdose ^[1].

The practice has grown without a research base. Dr. Shauna Levy, medical director for the Tulane Weight Loss Center, says there are no scientific studies looking at the efficacy and safety of microdosing GLP-1s. That does not mean it does not work, she says, but that the medical community does not know. Even if it does cause weight loss or a reduction in inflammation, she says, it is unclear whether those results persist long-term or whether the practice causes harm ^[1].

Levy says the word itself is a problem. "Microdosing GLP-1s is almost becoming this buzz word that carries inconsistent meaning," she says, adding that some use it as a marketing tool so people think they are not on a full dose. She also worries that people pay for a cheaper dose, find it does not work, and conclude "here's one more thing that's not working for me" ^[1].

Cost and side effects drive much of the interest. Brand-name GLP-1s run around $10,000 a year or more out of pocket, and roughly $300 to $1,200 a year when insurance covers them ^[1]. Many insurance plans pay only for a diabetes diagnosis, not obesity ^[1]. At the standard FDA-approved doses, common side effects include nausea, diarrhea and fatigue ^[1].

In 2025, telehealth companies including Fridays, Noom and Found Health began offering GLP-1 protocols at lower doses and lower costs ^[1]. Smaller doses often come from compounding pharmacies that make their own versions of FDA-approved drugs. That allows dose customization but is not subject to the same reviews for safety, efficacy or consistency, and may carry added risks related to quality control, potency variation or contamination ^[1].

The Times also described Monika Awadalla, a 31-year-old caretaker in Huntington Beach, who has bought compounded tirzepatide for about a year and a half from an illegal manufacturer in China that she found through a Facebook group. She went from 245 pounds to 140 pounds; the manufacturer charges $290 for 10 vials, which lasts her about a year ^[1].

Why it matters for patients

Microdosing has no agreed definition, so two people using the term may be taking very different amounts of semaglutide or tirzepatide ^[1]. Levy's stated concern is who is writing the prescription and whether anyone is following the patient over time; she says care should come from a clinician licensed by the American Board of Obesity Medicine, and that a lot of GLP-1 prescriptions are written by professionals untrained in obesity medicine ^[1].

The supply route also changes the risk picture. Compounded and illegally imported products do not carry the same safety, efficacy or consistency review as FDA-approved drugs, and may vary in potency or be contaminated ^[1].

Levy says GLP-1s are "fantastic" for treating obesity when prescribed correctly, and that gastrointestinal effects in her patients are common but generally tolerable ^[1]. She also says she believes the criteria for obesity should expand so more people qualify for the drugs through proper channels ^[1].

What happens next

Whether formal trials of microdosing semaglutide or tirzepatide are planned or underway has not been reported ^[1]. The Times reports that the trend began after Wegovy's 2021 FDA approval for obesity and has continued to spread since then ^[1].