Phentermine Industry Worth $200 Million a Year Being Eroded by Ozempic and Wegovy

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By Jacob Maslow

The phentermine industry, including sales of generic phentermine and brand-name drugs like Adipex-P, is estimated to generate over $200 million in revenue annually in the United States. Some key facts about the phentermine market:

Phentermine was approved for weight loss in 1959 and has been on the market for over 60 years. It remains one of the most commonly prescribed weight loss medications today.

Phentermine is available as a generic, so many patients are prescribed the lower-cost generic form. However, brand-name drugs like Adipex-P, Oby-Cap, T-Diet, etc., are also still marketed and provide revenue. 

Adipex-P, produced by TevaUSA, is the most popular brand name phentermine drug. Nearly 4 million Adipex-P prescriptions were filled in the U.S. in 2019, suggesting over $100 million in sales for that brand alone.

The average retail price for 30 phentermine 37.5 mg capsules (generic) is around $25 to $50. Brand-name phentermine drugs range from $75 to $300 for the same amount. Prices vary between pharmacies.

Phentermine is approved for short-term use, but many patients remain on the medication for 6 months to over a year so they may purchase multiple cycles of the drug for several hundred to a few thousand dollars in total treatment cost. Average phentermine weight loss results for 3 months are around 10 – 15% of your starting body weight.

In the U.S., phentermine requires a prescription and is not covered by most insurance plans because it is prescribed for weight loss and cosmetic purposes rather than to treat a medical condition. Patients pay full out-of-pocket costs.

In 2020, the FDA approved two new prescription weight loss pills – Wegovy and Belviq. While these may eventually compete with and draw some revenue from phentermine, phentermine remains substantially more affordable and commonly prescribed. 

The annual revenue generated from phentermine could decline in coming years with increasing competition from newer weight loss drugs, rising public interest in lifestyle interventions, and growing concerns about side effects or abuse potential. However, as obesity rates continue to increase worldwide, the need for pharmacological weight management options will likely sustain at least some level of demand and sales.

New Weight Loss Drugs

New injectable weight-loss drugs like Ozempic (semaglutide) and Wegovy (higher-dose semaglutide) are poised to impact the weight-loss drug market, including phentermine sales significantly. Some projections for Ozempic and Wegovy:

Ozempic, approved for diabetes in 2017 and weight loss in 2021, is expected to generate over $6 billion in revenue for Novo Nordisk by 2025. Up to half of this may come from weight loss prescriptions, suggesting potential lost sales of $3 billion or more annually. 

Wegovy, approved in 2021 for chronic weight management, is projected to produce at least $3 billion in annual revenue for Novo Nordisk within a few years. This would represent a sizable portion of the total weight loss drug market.

Ozempic and Wegovy may capture a large share of the existing phentermine market due to their superior efficacy for weight loss – potentially 15-20% total body weight loss vs. only 3-9% for phentermine. Even with high costs, this increased effectiveness is appealing to many patients and physicians.  

Unlike phentermine, Ozempic and Wegovy are injectable drugs that work by activating natural appetite-suppressing gut hormone pathways. This innovative approach to weight loss is gaining interest and support in the medical community. Injectables may be seen as a legitimate medical option rather than the potentially stigmatizing diet pills of the past.

While inexpensive, phentermine has more limited effectiveness and additional safety/abuse concerns given its central nervous system stimulation mechanism. Ozempic and Wegovy were specifically developed and approved as anti-obesity medications with tighter controls. This may make physicians and patients more comfortable with their long-term use.

However, phentermine will likely remain an option for some, especially those unable to afford or accept the risks/side effects of injectables like Ozempic and Wegovy or prefer an oral medication. Phentermine may continue to generate $200 million or more in annual sales for the foreseeable future. 

Competition from other new weight loss drugs in development may also impact future Ozempic, Wegovy, and phentermine sales. More treatment options could reduce revenue for currently available drugs and expand the total weight loss market.

Ozempic and Wegovy sales are poised for strong growth and may significantly reduce phentermine revenue over the next decade. However, phentermine is still likely to retain some long-term demand and sales, especially at lower price points. The weight loss drug landscape continues to evolve, with many open questions about how new and existing medications will compete and shape the market in years to come. No easy answers or silver bullets have yet emerged in the fight against obesity.

In summary, after over 60 years in the U.S. market, brand name and generic phentermine continue to produce between $200 million to $500 million per year in revenue and showing little signs of slowing soon. Phentermine remains an important, affordable treatment option.


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