Adipex-P Is a Prescription Weight Loss Medication

Adipex-P (Phentermine Hydrochloride) is a prescription appetite suppressant used for short-term weight management in adults with obesity.

It's one of the most widely prescribed weight loss medications in the United States, and it's been around for decades. But if you're considering Adipex-P — or your doctor just prescribed it — you probably have questions. This guide covers everything you need to know in 2026, from what it is and how to take it to how much it costs.

What Is Adipex-P?

Here are the basics:

• Brand name: Adipex-P
• Generic name: Phentermine Hydrochloride
• Drug class: Sympathomimetic amine anorectic (a type of CNS stimulant)
• Manufacturer: Teva Pharmaceuticals USA, Inc.
• DEA Schedule: Schedule IV controlled substance
• Other brand names: Lomaira (8 mg), Suprenza (orally disintegrating tablet)

Phentermine was first approved by the FDA in 1959, making it one of the oldest weight loss medications still in use. It's chemically related to amphetamine but has a much lower potential for abuse, which is why it's classified as Schedule IV rather than Schedule II.

What Is Adipex-P Used For?

Adipex-P is FDA-approved for the short-term management of obesity (typically a few weeks) as an add-on to caloric restriction and exercise. It's prescribed for adults who meet these criteria:

• BMI of 30 or higher (obese), or
• BMI of 27 or higher with at least one weight-related condition, such as high blood pressure, type 2 diabetes, or high cholesterol

Adipex-P is not a standalone solution — it's meant to be used alongside a reduced-calorie diet and increased physical activity. Your doctor may also recommend behavioral counseling as part of your weight loss plan.

Some doctors prescribe Phentermine for longer than a few weeks off-label, but this is at the prescriber's discretion and requires ongoing monitoring.

How Is Adipex-P Taken?

Adipex-P comes in several forms:

• Adipex-P 37.5 mg tablets (scored, so they can be split)
• Adipex-P 37.5 mg capsules
• Lomaira 8 mg tablets (lower dose, taken three times daily)
• Suprenza 15 mg or 30 mg orally disintegrating tablets

Standard dosing:

• Take one 37.5 mg tablet or capsule daily, before breakfast or 1–2 hours after breakfast
• Alternatively, your doctor may prescribe half a scored tablet (18.75 mg) once daily
• For Lomaira: take 8 mg three times daily, 30 minutes before meals

Important tips:

• Take your dose early in the morning to avoid insomnia
• Do not take it late in the evening
• Swallow tablets whole or split along the score line — do not crush capsules
• Do not increase your dose without your doctor's approval

For more on how the medication works in your body, read our explainer on how Adipex-P works.

Who Should Not Take Adipex-P?

Adipex-P is not safe for everyone. It is contraindicated in patients with:

• History of cardiovascular disease (heart disease, stroke, arrhythmias, uncontrolled high blood pressure, congestive heart failure)
• Hyperthyroidism (overactive thyroid)
• Glaucoma
• History of drug abuse
• Pregnancy or breastfeeding (FDA Category X)
• Current use of or use within 14 days of MAO inhibitors
• Known allergy to sympathomimetic amines
• Agitated states
• Pulmonary hypertension

It's also not recommended for children under 16 or for patients with severe kidney or liver problems. Older adults should use it with caution due to increased sensitivity to cardiovascular effects.

Make sure to tell your doctor about all medications you're taking, including over-the-counter drugs and supplements. Adipex-P has important drug interactions you should know about.

How Much Does Adipex-P Cost?

Here's what you can expect to pay in 2026:

• Brand-name Adipex-P: Around $115 retail for 30 tablets
• Generic Phentermine 37.5 mg: $4 to $15 for 30 tablets with discount coupons (as low as $1.80 with GoodRx Gold)
• With insurance: Most plans cover generic Phentermine at Tier 1 or Tier 2 with copays of $5 to $25

The generic version is widely available and much cheaper. Unless your doctor specifically requires brand-name Adipex-P, generic Phentermine is the same active ingredient at a fraction of the cost.

For detailed savings strategies, check out our guide on coupons, discounts, and patient assistance for Adipex-P.

What Are the Side Effects?

Common side effects include dry mouth, insomnia, constipation, increased heart rate, restlessness, and headache. Serious but rare side effects include primary pulmonary hypertension, heart valve problems, and severe blood pressure spikes.

For a complete breakdown, read our detailed guide on Adipex-P side effects.

Final Thoughts

Adipex-P is a well-established, affordable weight loss medication that works best as part of a comprehensive plan including diet, exercise, and medical supervision. It's not a long-term solution, but for many patients, it provides the jump-start they need to build healthier habits.

If your doctor has prescribed Adipex-P, you can use Medfinder to find a pharmacy near you with it in stock — and start your treatment without delay.