Lancet Review Flags Lean Mass Loss, Access Barriers for Women on GLP-1s

A narrative review published September 29, 2026, in The Lancet Obstetrics, Gynaecology, & Women's Health found that the global rollout of GLP-1 receptor agonists, whose users are predominantly women, "has outpaced the development of guidance for women," and that evidence on how the drugs perform in some groups of women remains limited.¹ The paper, led by Claire L. Meek, PhD, of the Leicester Diabetes Research Centre at the University of Leicester in the UK, is the second in a two-paper series on the drugs and women's health.

The authors searched PubMed, Embase, and Google Scholar through February 28, 2026, without applying systematic review criteria, so the paper offers a synthesis of existing literature rather than new trial data.

Why Does Lean Mass Matter?

Most trials show that about 70% of weight lost on these drugs is fat and 30% is lean mass, the review notes. The authors say it is unclear whether the same split holds in people with lean type 2 diabetes and that further lean mass loss could contribute to frailty and functional disability, especially in older women.

Preventing muscle loss requires adequate protein intake and consistent resistance training, the authors write, but they add that these measures are hard to sustain over the long term for many women because of deprivation, limited finances, and social attitudes toward women and exercise.

What Are Nutrition Experts Saying About Supplement Support?

The nutritional side of GLP-1 use was also a topic at The Outlook on Active Nutrition, where sports nutritionist Doug Kalman, PhD, RD, FISSN, said the drugs cut caloric intake by roughly 15% to 40%, with early-treatment intake often falling to 800 to 1,200 calories a day.²

Kalman cited data indicating that after six months to a year on therapy, about 98% of users had insufficient vitamin D and potassium intake, 94% insufficient choline, roughly 90% insufficient magnesium, and 88% insufficient iron. He also said about 22.5% of long-term users develop a diagnosed vitamin or mineral deficiency.

On muscle, Kalman cited data indicating that roughly 38% of early weight loss is muscle, a higher share than the 30% lean mass figure the Lancet authors cite. He pointed to resistance training, protein intake of 1.2 to 1.6 grams per kilogram of body weight, and 20 to 30 grams of daily fiber as evidence-based strategies. Among supplements, Kalman pointed to a recently published trial in which people taking GLP-1 drugs lost less muscle with beta-hydroxy beta-methylbutyrate (HMB) than with placebo, and he also named creatine monohydrate, which he said has both a mechanistic rationale and research behind it for preserving muscle. He also noted that no standard monitoring protocol exists for GLP-1 patients comparable to bariatric surgery care, and that about 35% to 50% of patients discontinue therapy within a year, a population he suggested nutrition companies are positioned to support.

What Barriers to Access Did the Authors Identify?

Cost is the main barrier in low- and middle-income countries (LMICs) and among socioeconomically deprived groups in high-income countries, according to the review. The authors cite manufacturing estimates suggesting several of these drugs could be produced sustainably for roughly $1 to $70 a month, depending on formulation, while retail prices in many LMIC settings exceed $90 a month. They also cite an analysis across 99 countries indicating that nearly 80% of adults who meet clinical eligibility criteria live in LMICs, where access remains minimal.

The review also cites World Health Organization reports that shortages are increasing the presence of counterfeit products, and says women seeking cheaper options often turn to compounded versions without knowing the dosing and contamination risks. These products are occasionally misrepresented as approved by the FDA.

References

1. Meek CL, Anjana RM, Chandiwana N, et al. Global barriers to GLP-1 receptor agonist treatment in women: access, safety, and equity. Lancet Obstet Gynaecol Womens Health. Published online September 29, 2026. doi:10.1016/S3050-5038(26)00228-1
2. McEvoy E. Muscle loss, micronutrient gaps, and the GLP-1 opportunity for supplement brands. Nutritional Outlook. September 28, 2026. Accessed October 5, 2026. https://www.nutritionaloutlook.com/view/muscle-loss-micronutrient-gaps-the-glp-1-opportunity-supplement-brands
3. Johnson B. Providing clarity in a noisy nutrition landscape. Nutritional Outlook. October 5, 2026. Accessed October 5, 2026. https://www.nutritionaloutlook.com/view/providing-clarity-in-a-noisy-nutrition-landscape