Hair loss on Foundayo™

Hair loss in the Foundayo™ documents

Section 6.1 of the label pools Trials 1 and 2, with 3,155 adults on Foundayo™ and 1,576 on placebo for up to 72 weeks ^[1]. The hair loss row carries a footnote saying it includes related terms, so it covers more than one way of recording thinning or shedding. The Medication Guide lists hair loss among the most common side effects ^[2].

Outside the US there are no figures yet. The European Medicines Agency’s committee recommended approval on 15 October 2026 for weight management and type 2 diabetes, but there is no EMA product information yet ^[3], and Health Canada’s database has no entry for Foundayo™ or orforglipron ^[4].

Women and men

A separate paragraph in section 6.1 breaks the figure down by sex. On Foundayo™, 7% of women reported hair loss against 0.9% of men; on placebo the figures were 3% and 0.7% ^[1]. The gap between tablet and placebo was therefore mostly among women, where the rate more than doubled.

This matters when reading the headline 4% to 5%. The pool was 41% men ^[1], so the overall figure blends a fairly common reaction in women with a rare one in men. For a woman deciding what to expect, the 7% figure is the more relevant one. The label does not explain the gap.

What the trial registries add

On ClinicalTrials.gov, hair loss appears under the single term alopecia. The ATTAIN weight trials posted only events reaching 5% in at least one group, while two diabetes trials posted every event ^[5][6][7][9]. In ATTAIN, the 6, 12 and 36 mg trial doses correspond to Foundayo™ 5.5, 9 and 17.2 mg ^[1].

Reading the registry pattern

• ATTAIN-1, the trial without diabetes, is where alopecia stood out: it roughly doubled against placebo and edged up with dose ^[5].
• The absence of an ATTAIN-2 row does not mean nobody lost hair; it means no group reached 5% ^[6].
• In the diabetes trials, alopecia was rare in every group, including the comparators ^[7][9]. Weight loss there was also smaller: 4.5% to 7.6% on orforglipron after 40 weeks in ACHIEVE-1, against 1.7% on placebo ^[8].
• That pattern fits the label’s link with weight reduction, but the trials differ in length, population and listing rules, so it cannot prove it.

The link to weight loss

The label states that hair loss on Foundayo™ was associated with weight reduction and does not describe a direct effect of orforglipron on hair ^[1]. Table 6 shows the scale of that weight change. In Trial 1, average weight fell by 7.4%, 8.3% and 11.1% on the three doses after 72 weeks, against 2.1% on placebo, and 35.9% of people on 17.2 mg lost at least 15% of their starting weight, against 6% on placebo ^[1]. In Trial 2, with type 2 diabetes, the falls were 5.1%, 7% and 9.6%, against 2.5% ^[1]. Section 12.2 adds that more fat than lean mass was lost ^[1].

The two trials also enrolled different people. Trial 1 had an average age of 45 and 64% women; Trial 2 an average age of 57 and 47% women ^[1]. One detail the label leaves unexplained: hair loss changed little between doses even though weight loss was clearly larger on the top dose.

Why weight loss can thin hair

• From the label: hair loss tracked with weight reduction, and Foundayo™ lowers food intake, likely by reducing appetite ^[1]. The label goes no further than that association.
• Suggested but not measured: Cleveland Clinic lists rapid weight loss, restrictive diets and fad diets low in protein among triggers of telogen effluvium, in which many hairs move early into the resting phase and then shed ^[11]; MedlinePlus names crash diets short on protein too ^[10]. Whether the shedding seen with orforglipron is telogen effluvium has not been studied.
• General knowledge: telogen effluvium often shows two to three months after the trigger, most often thins the top of the head, usually spares the hairline, and leaves the scalp itself looking healthy ^[11]. Cleveland Clinic adds that women aged 30 to 60 are more prone to a long-lasting form without a clear cause ^[11].

Other causes of thinning hair

MedlinePlus lists hereditary pattern thinning, physical or emotional stress, high fever or severe infection, childbirth, major surgery or illness, and medicines including retinoids, birth control pills, beta-blockers, calcium channel blockers, some antidepressants and NSAIDs ^[10]. Unusual patterns can point to alopecia areata, anaemia, lupus, thyroid disease, hormone changes, scalp ringworm, frequent blow-drying or tight hairstyles ^[10]. Cleveland Clinic adds an overactive or underactive thyroid and stopping birth control pills as triggers ^[11].

Because several of these can overlap with a weight-loss programme, for example a new medicine, a recent illness or a stressful period, it helps to note them alongside the date you first noticed shedding.

What general sources say tends to help

Cleveland Clinic says the first step is to find the trigger, and that once it is dealt with most telogen effluvium settles without treatment and the hair grows back ^[11]. For prevention it mentions enough protein, coping with stress, enough sleep and avoiding extreme or restrictive diets, and advises asking your provider before adding vitamins or supplements ^[11]. It names a scalp treatment, minoxidil, as an option; that is a conversation for a pharmacist or doctor ^[11].

MedlinePlus notes that hair lost through illness or medicines usually grows back once the cause ends, and that hairstyles, hairpieces or a hat can cover thinning in the meantime ^[10]. Neither source sets a weight-loss speed, and the Foundayo™ label leaves dose decisions to the prescriber ^[1].

What the label does not cover

• When hair loss started or how long it lasted.
• Whether hair regrew during treatment or after stopping.
• Which related terms were grouped under the row.
• Whether anyone stopped Foundayo™ because of hair loss; no stopping rate is given ^[1].

Foundayo™ is a trademark of Eli Lilly and Company. PepLabo is not affiliated with or endorsed by Eli Lilly and Company.

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