Feature|Articles|April 6, 2026

Why Do a Significant Number of GLP-1 Users Stop Taking the Medication in the First Year?

Key Takeaways

  • Market momentum continues through regulatory and access innovations, including accelerated approval of a higher-dose Wegovy formulation and subscription-based telehealth distribution strategies.
  • Persistence drops when patients approach GLP-1 therapy as a “panacea,” anticipating predictable, rapid weight loss without appreciating variability in response.
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Phenomix CEO Mark Bagnall discusses the reasons for GLP-1 failure and why it’s common for patients to stop taking the medication.

GLP-1 drugs continue to dominate the pharmaceutical landscape. The medication is popular for its weight loss applications, and major pharmaceutical companies continue to introduce new versions of these medications. In late March, FDA approved a high dose injectable version of Wegovy through its accelerated approval program. Around the same time, Novo Nordisk announced a new multi-month subscription program for Wegovy for telehealth providers.

Clearly, the drugs are still popular. However, new data collected by Phenomix and the Mayo Clinic suggests that patients seeking the drug may not be fully aware of how the medication works and what the side effects are.

Phenomix’s CEO Mark Bagnall spoke with Pharmaceutical Executive about this data and what the impact is on GLP-1 users.

Pharmaceutical Executive: Why do a significant number of GLP-1 users stop taking the medication in the first year?
Mark Bagnall: In our experience, it's a combination of the cost of medication and unforeseen effects. A lot of folks who start using the drug think of it as a panacea. It's going to be easy. My friend lost 30 pounds, I'm going to lose 30 pounds too.

However, a number of people (between 10-20%) suffer from severe side effects, such as nausea, vomiting, etcetera. Another fairly significant number of people just don't see the weight loss that they would like to have seen. Some may see a little bit, but some of them, unfortunately, see none.

That combination is expensive. People who say, “I'm struggling with side effects,” or “I'm not really seeing enough weight loss” will tend to stop using the medication. This is unfortunate, because it has cost them some money and some time.

There are people who have struggled with managing weight for a long time, and to have thought that you could eventually see a benefit than not seen it must be awfully disappointing.

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