Key takeaways:
Phentermine (Adipex-P, Lomaira) is one of the most affordable oral weight-loss medications. It’s available as brand-name Lomaira as well as a lower-cost generic (in certain doses).
How much you’ll pay for phentermine depends on factors such as your dosage form, pharmacy, and insurance coverage.
Without insurance, a 30-day supply of 37.5 mg phentermine tablets costs an average of $37.81. You could pay as little as $14.40 for the same prescription with a free GoodRx discount. A manufacturer savings card is also available for brand-name Lomaira.
Prescription glucagon-like peptide-1 (GLP-1) medications such as Wegovy (semaglutide) and Zepbound (tirzepatide) are getting all the headlines right now. But weight-loss medications aren’t new. In fact, there are a number of effective and more affordable prescription weight-loss treatments — including pills — that have been around for decades.
One common option is phentermine (Adipex-P, Lomaira). But how much does phentermine cost? And does insurance cover it? Here’s what you should know.
How much does phentermine cost without insurance?
Phentermine comes in several doses and dosage forms. Without insurance, a 30-day supply of phentermine 37.5 mg tablets costs an average of $37.81.
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The chart below shows the average cash price of common brand-name and generic forms of phentermine.
What factors affect the cost of phentermine?
What you pay for phentermine depends on several factors, including:
Brand-name vs. generic form: Phentermine is available as a lower-cost generic in most doses. But Lomaira is only available as a brand-name medication. Generic forms of phentermine are typically more affordable than brand-name products.
Dose and dosage form: The cost of phentermine can also vary depending on what dose and form you’re prescribed. It comes in both capsules and tablets, and the price may vary between these dosage forms, as well as your daily dose.
Location: Where you live can affect the cost of your prescription medications. For example, according to GoodRx research, people in Little Rock, Arkansas, tend to pay more for prescription medications than people in Houston, Texas.
Pharmacy: Pharmacies negotiate their own pricing for prescription medications. So the cash price of phentermine can vary among different pharmacies, even if they’re located in the same neighborhood. GoodRx can help you compare prices among pharmacies in your area to help you find the lowest price.
Is phentermine covered by insurance?
Some health insurance plans cover phentermine. Nearly all commercial plans not purchased through an Affordable Care Act (ACA) marketplace and about half of Medicaid plans cover this medication.
Step therapy (requiring you to try other medications first before covering phentermine) isn’t common. But some plans, Medicaid in particular, may require prior authorization. This means your prescriber must submit information to the insurance plan about your prescription before coverage is approved.
If you have insurance that covers phentermine, it can help reduce what you pay for your medication. But even with insurance, you may still have out-of-pocket expenses, such as a copay or coinsurance. These expenses are often based on whether phentermine falls in a higher tier on your plan’s formulary (list of covered medications).
Checking your coverage in advance can help you know whether phentermine is covered and what you can expect to pay. You can typically access your summary of benefits and formulary online or by calling the help desk number on your prescription insurance card.
How different insurance plans cover phentermine
The following chart shows the percentage of enrollees with coverage for phentermine 37.5 mg tablets for different types of insurance plans. It also shows the likelihood of having prior authorization and step therapy requirements.
Insurance type | Enrollees covered for phentermine 37.5 mg tablets | Enrollees required to get prior authorization | Enrollees required to do step therapy |
|---|---|---|---|
Commercial plans (not including plans purchased through an ACA marketplace) | 90% | 16.3% | 0% |
27.5% | 11% | 0% | |
Medicare, including original Medicare and Medicare Advantage plans | 3% | 2.2% | 0% |
Medicaid, including state-run and managed care plans | 51.2% | 36% | 2.1% |
Source: Managed Markets Insight & Technology, LLC™, as of May 12, 2025. (See methodology below.)
Tips if your medication isn’t covered by insurance
If your insurance doesn’t cover phentermine, you still have options:
Ask your prescriber to submit a letter of medical necessity or request a formulary exception from your insurance provider. If your request is denied, submit an appeal.
Use a GoodRx discount to lower your prescription cost (more on that next).
Ask your prescriber about phentermine alternatives that your insurance may cover, such as Qsymia (phentermine / topiramate).
When it’s time for open enrollment, compare different health insurance plans to find one that provides the coverage you need.
Ways to save on phentermine
There are a couple of ways to save on your phentermine prescription.
1. Use a GoodRx coupon
A free GoodRx discount may help you save on the cost of phentermine. The table below shows the lowest GoodRx price at certain pharmacies (versus the average cash price) for the most common doses and forms of phentermine.
Phentermine product and quantity | Phentermine average cash price | Phentermine GoodRx low price* |
|---|---|---|
Phentermine 15 mg, 30 capsules | ||
Phentermine 30 mg, 30 capsules | ||
Phentermine 37.5 mg, 30 capsules | ||
Phentermine 37.5 mg, 30 tablets | ||
Lomaira 8 mg, 90 tablets |
*Note: Phentermine is a controlled substance, and some states do not allow coupons for these medications.
To save with a GoodRx discount:
Visit www.goodrx.com or download the GoodRx app.
Search for “phentermine” or “Lomaira”
Select your prescribed dose, form, and quantity.
Compare pharmacy prices in your area to find the best deal.
Choose if you want to receive the discount card by text or email. You can also take a screenshot on your phone.
To avoid delays, provide the discount information to the pharmacy before you go in to pick up your medication.
Keep in mind: GoodRx savings may vary by pharmacy and geographic location. The GoodRx website and app can help you compare prices in your area. In addition, phentermine is a controlled substance, and some states do not allow coupons for these medications.
2. Enroll in GoodRx Companion
You can access discounted prescription medications with a GoodRx Companion subscription. Over 250 medications (including some forms of phentermine) are available for free, with hundreds more for under $10 per month. Keep in mind that prices and availability may vary by pharmacy and geographic location.
The GoodRx Companion program also includes benefits to help you cut your self-pay costs. You’ll have access to lower prices for online care visits, discounts on dental care, and other health service savings.
3. Use a manufacturer savings card
You can pay as little as 50 cents per pill for brand-name Lomaira with a savings card from the manufacturer. That’s $45 per month if you take Lomaira 3 times a day.
To be eligible for this program, you must:
Be a resident of the U.S., including Puerto Rico, the U.S. Virgin Islands, and Guam
Not have government-sponsored insurance coverage (but you may use this card if you’re paying out of pocket for Lomaira and no claim is submitted to or reimbursed by a government-funded insurance plan)
You can enroll in the Lomaria savings program online or call 1-844-566-2472 for more information.
4. Tap into your HSA, FSA, or HRA
If you have a health savings account (HSA), flexible spending account (FSA), or health reimbursement arrangement (HRA), you can use it to help cover your out-of-pocket costs for phentermine. These tax-advantaged healthcare accounts let you pay for eligible expenses with tax-free dollars.
Pay directly with your HSA or FSA card at the pharmacy, or cover the cost yourself and request reimbursement. The funds in HSAs and some HRAs roll over annually. But you have to use FSA dollars before the plan’s deadline or they’ll expire.
Frequently asked questions
Yes, you must have a prescription from a healthcare professional to get phentermine. Since phentermine is a controlled substance, there may be limits on who can prescribe it and how often you can fill your prescription. Check your state laws or speak with a healthcare professional in your area for more information about local rules for controlled substances.
Ozempic (semaglutide) is FDA approved to treat Type 2 diabetes, while phentermine is approved for weight loss. Wegovy is the form of semaglutide approved for weight loss. Semaglutide and phentermine have different risks and benefits to consider. One may be a safer choice than another based on your medical history.
For example, phentermine isn’t recommended for people living with certain types of heart conditions or a history of substance misuse. Ozempic or Wegovy may actually be beneficial for these issues. But phentermine comes as a lower-cost generic. Your prescriber can help you find the right fit for your needs based on your medical history and health goals.
You should avoid taking phentermine with stimulants, such as some ADHD medications. Phentermine can also interact with some antidepressants and tramadol (Ultram). You should avoid or limit alcohol while taking phentermine. It’s also best not to combine other weight-loss medications with phentermine unless your prescriber recommends it. Also, phentermine isn’t recommended if you have a history of heart problems or substance misuse. Review your medication list with your prescriber before starting phentermine to make sure it’s a safe option for you.
Yes, you must have a prescription from a healthcare professional to get phentermine. Since phentermine is a controlled substance, there may be limits on who can prescribe it and how often you can fill your prescription. Check your state laws or speak with a healthcare professional in your area for more information about local rules for controlled substances.
Ozempic (semaglutide) is FDA approved to treat Type 2 diabetes, while phentermine is approved for weight loss. Wegovy is the form of semaglutide approved for weight loss. Semaglutide and phentermine have different risks and benefits to consider. One may be a safer choice than another based on your medical history.
For example, phentermine isn’t recommended for people living with certain types of heart conditions or a history of substance misuse. Ozempic or Wegovy may actually be beneficial for these issues. But phentermine comes as a lower-cost generic. Your prescriber can help you find the right fit for your needs based on your medical history and health goals.
You should avoid taking phentermine with stimulants, such as some ADHD medications. Phentermine can also interact with some antidepressants and tramadol (Ultram). You should avoid or limit alcohol while taking phentermine. It’s also best not to combine other weight-loss medications with phentermine unless your prescriber recommends it. Also, phentermine isn’t recommended if you have a history of heart problems or substance misuse. Review your medication list with your prescriber before starting phentermine to make sure it’s a safe option for you.
The bottom line
Phentermine (Adipex-P, Lomaira) is one of the most affordable oral weight-loss medications. It’s available as brand-name Lomaira as well as a lower-cost generic (in certain doses).
How much you’ll pay for phentermine depends on factors such as your dosage form, pharmacy, and insurance coverage. Without insurance, a 30-day supply of 37.5 mg phentermine tablets costs an average of $37.81. You could pay as little as $14.40 for the same prescription with a free GoodRx discount. A manufacturer savings card is also available for brand-name Lomaira.
Why trust our experts?
Methodology
We obtained national prescription coverage data for each medication from Managed Markets Insight & Technology (MMIT). The data reflects health insurance coverage as of May 2025.
We calculated the percentage of enrollees in plans that cover each medication by dividing the number of enrollees covered for the medication within a specific insurance channel (e.g., ACA, Medicare, Medicaid) by the total number of enrollees in all plans within that channel.
We determined the percentage of enrollees in plans with a prior authorization requirement by calculating the proportion of enrollees in plans that required prior authorization for the medication within each channel.
Finally, we measured the percentage of enrollees in plans with a step therapy requirement by calculating the proportion of enrollees in plans that imposed step therapy requirements for the medication in each channel.
These estimates, derived from national MMIT coverage data, provide insight into health insurance coverage for each medication. They take into account restrictions such as prior authorization, step therapy, and quantity limits. The percentages are expressed relative to the total number of enrollees covered by various insurance channels, including the ACA, commercial (excluding ACA) plans, Medicare, and Medicaid (both state-run and managed care plans).
References
Fourie, A., et al. (2023). Potential drug-drug interactions with phentermine among long-term phentermine consumers: A retrospective analysis. South African Medical Journal.
Healthcare.gov. (n.d.). Using your health insurance coverage: Getting prescription medications.
KVK Tech. (n.d.). The Lomaira Lo-Cost Access Program.
Medicaid.gov. (n.d.). Managed care.
