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Phentermine alternatives: What can I take instead of phentermine?

Phentermine doesn't work for everyone. Contrave, Lomaira, Saxenda, Wegovy, and Zepbound are some phentermine alternatives. Get the full list here.
Karen Berger medical writer and reviewer headshot
By | Updated on Mar. 21, 2025

Key takeaways

  • Phentermine is a prescription medication used for weight loss. However, it may not be the best option for everyone.

  • Alternatives to phentermine include FDA-approved prescription medications such as Contrave, Lomaira, Saxenda, Wegovy, or Zepbound. Each has different side effect profiles and dosing schedules suitable for different individuals.

  • Common adverse effects of phentermine include dry mouth, vomiting, and constipation or diarrhea. People with a history of substance use disorder should not take phentermine.

  • Natural alternatives to phentermine, such as dietary supplements, are generally not recommended due to their lack of effectiveness and potential harm. Supplements are not held to the same safety and efficacy standards as prescription medications.

In this article:

Phentermine is a prescription drug commonly used for weight loss. It is available as a generic drug and under the brand names Adipex-P and Lomaira. As a Schedule IV controlled substance, phentermine has the potential for abuse and dependence and should not be used in people with a history of substance use disorder. Phentermine is chemically related to amphetamine and other central nervous system (CNS) stimulants that are often misused. Phentermine is FDA-approved for short-term use, but healthcare providers sometimes prescribe it for longer periods of time. 

Phentermine may not be the most suitable drug for everyone. The good news is that if you are looking for an alternative to phentermine, there are various other options available. 

What can I take in place of phentermine?

Other types of medications are available if you are looking for a phentermine alternative. The table below compares phentermine with common alternatives. All of the weight loss drugs listed are FDA-approved prescription medications. Your healthcare provider can advise you on which medication may be best for you. 

Compare phentermine alternatives
Drug name Uses Dosage Savings options
Adipex-P (phentermine) Short-term treatment of obesity 15 to 37.5 mg by mouth in the morning (dosage may start lower and be slowly increased to this dosage) Phentermine coupons
Contrave (naltrexone and bupropion) Chronic weight management  Week 1: 1 tablet in the morning

Week 2: 1 tablet in the morning and 1 tablet in the evening

Week 3: 2 tablets in the morning and 1 tablet in the evening

Week 4 and thereafter: 2 tablets in the morning and 2 tablets in the evening

 Contrave coupons
Lomaira (phentermine) Short-term treatment of obesity 8 mg by mouth 3 times daily Lomaira coupons
Qsymia (phentermine and topiramate) Weight-loss and long-term weight maintenance Varies Qsymia coupons
Saxenda Chronic weight management 0.6 mg injected subcutaneously daily for 1 week, then the dose is increased gradually to a target (and maximum) dose of 3 mg injected daily Saxenda coupons
Wegovy (semaglutide) Weight-loss and long-term weight maintenance 

Cardiovascular risk reduction

 0.25 mg injected subcutaneously every week for 4 weeks, then gradually increased by healthcare provider to a maintenance dose of 1.7 or 2.4 mg once weekly Wegovy coupons
Zepbound (tirzepatide) Weight-loss and long-term weight maintenance

Obstructive sleep apnea

 2.5 mg injected subcutaneously every week for 4 weeks, then gradually increased by healthcare provider to a maintenance dose of 5, 10, or 15 mg once weekly Zepbound coupons

Other alternatives to phentermine

Reasons to consider a phentermine alternative

Sometimes, an individual may be interested in trying a different treatment than phentermine. Some patients may not be able to take phentermine due to a contraindicated medical condition, such as an overactive thyroid. Others may not see the desired effects of phentermine and may want to seek the best alternative to see if a different drug is more effective. 

Others may experience side effects that are bothersome or do not go away. Some of the common adverse effects of phentermine include:

  • Dry mouth 
  • Unpleasant taste in the mouth
  • Constipation or diarrhea
  • Vomiting

Sometimes, a serious side effect may occur, requiring emergency or urgent medical attention. Severe side effects may include:

  • Allergic reactions
  • Increased blood pressure
  • Heart palpitations
  • Feeling restless
  • Dizziness 
  • Shaking 
  • Trouble sleeping
  • Shortness of breath 
  • Chest pain
  • Swelling of the legs and ankles

Other weight-loss medications can be discussed with a healthcare professional for patients seeking an effective phentermine alternative. 

Top 5 phentermine alternatives

The following are some of the most common alternatives to phentermine.

1. Contrave (naltrexone and bupropion) oral tablet

Contrave contains two ingredients. Naltrexone, an opioid antagonist, and bupropion, an antidepressant, work on two areas of the brain that are involved in the appetite and reward system. Contrave is FDA-approved for chronic weight management and can be used in adults with a BMI of 30 or more—or adults with a BMI of 27 or more with at least one weight-related risk factor such as high blood pressure, high cholesterol, or Type 2 diabetes. 

Common side effects include nausea, constipation, diarrhea, headache, vomiting, dizziness, trouble sleeping, and dry mouth. 

Contrave has an FDA-required black box warning due to the risk of suicidal thoughts and behaviors associated with bupropion, its antidepressant ingredient. Patients taking Contrave should be closely monitored for mood changes, suicidal thoughts, or unusual behavior, especially in the first few months of treatment or after dose changes. Contrave is not approved for use in children or adolescents under 18. 

RELATED: Compare Contrave vs. phentermine

2. Lomaira (phentermine) oral tablet

Lomaira is a brand-name drug that contains phentermine, but in an 8 mg dose—a smaller dose that is taken three times daily—rather than the typical generic phentermine dose, which is generally a larger dose taken once daily. Lomaira is only available under the brand name. There is no equivalent generic 8 mg phentermine. 

The common side effects of Lomaira are the same as those of generic phentermine taken in larger doses, such as dry mouth, unpleasant taste, and stomach problems like vomiting, diarrhea, and constipation.

3. Saxenda (liraglutide) injection

Saxenda is a GLP-1 receptor agonist that contains the active ingredient liraglutide. It is approved for long-term weight management in adults with a BMI of 30 or more—or adults with a BMI of 27 or more with at least one weight-related risk factor. It can also be used in adolescents 12 years and older who weigh more than 60 kg (132 lbs) and have an initial BMI corresponding to 30 in adults. 

Common side effects of Saxenda include stomach problems, including nausea, vomiting, diarrhea or constipation, indigestion, stomach pain, and stomach virus. Other common side effects may include injection site reactions, headache, tiredness, and dizziness. Hypoglycemia (low blood sugar) may occur in patients with Type 2 diabetes who also use insulin or certain diabetes medications. 

Because Saxenda affects stomach emptying, ask your healthcare provider when you should time any oral medications.

Saxenda has a black box warning. The warning states that the drug causes thyroid C-cell tumors in rats. However, it is not known if Saxenda can cause thyroid tumors in humans. Saxenda should not be used in people with a history (or family history) of medullary thyroid carcinoma or in people with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). Individuals who use Saxenda should be alert to symptoms of thyroid tumors (such as a lump in the neck, hoarseness, shortness of breath, or trouble swallowing) and call their healthcare provider right away if any of these symptoms occur.

4. Wegovy (semaglutide) injection

Wegovy is a GLP-1 agonist that contains the ingredient semaglutide. Wegovy is a weekly injection that is FDA-approved for long-term weight management in adults with a BMI of 30 or more—or adults with a BMI of 27 or more with at least one weight-related risk factor. It is also FDA-approved for cardiovascular risk reduction (to lower the risk of stroke, heart attack, and heart-related death) in adults with heart disease and either obesity or overweight.

Common side effects include stomach problems such as nausea, vomiting, diarrhea or constipation, stomach pain, bloating, indigestion, gas, burping, reflux, and stomach virus. Other common Wegovy side effects may include low blood sugar (especially in those with Type 2 diabetes who use insulin or certain diabetes medicines), headache, fatigue, and dizziness.

Like Saxenda, Wegovy affects stomach emptying. Ask your healthcare provider when you should time any oral medications. Wegovy also has the same black box warning as Saxenda. 

Note: Wegovy is the only semaglutide drug FDA-approved for weight loss. Other FDA-approved drugs that contain semaglutide include:

  • Ozempic, which is FDA-approved for Type 2 diabetes, cardiovascular risk reduction, and kidney disease but is often prescribed off-label for weight loss
  • Rybelsus, which is FDA-approved for Type 2 diabetes

Compounded semaglutide drugs are not approved or regulated by the FDA.

5. Zepbound (tirzepatide) injection 

Zepbound (tirzepatide) is a once-weekly injection. It is classified as a glucose-dependent insulinotropic polypeptide (GIP) receptor and glucagon-like peptide-1 (GLP-1) receptor agonist, or GIP/GLP-1 receptor agonist. While many injectable drugs approved for Type 2 diabetes or weight loss are GLP-1 receptor agonists, Zepbound activates an additional pathway, which may help make it more effective. A 2024 study reported that people who used Zepbound lost an average of 20.2% of body weight, compared to 13.7% in those who used Wegovy, after 72 weeks.

Common side effects include nausea, vomiting, diarrhea or constipation, indigestion, stomach pain, tiredness, burping, heartburn, hair loss, injection site reactions, and allergic reactions. 

Because Zepbound affects stomach emptying, check with your healthcare provider if you need to change the timing of any other medicines you take. Also, women who take oral contraceptives (birth control pills) should add a barrier method of birth control (such as condoms) or use another form of effective birth control for 4 weeks after starting Zepbound and for 4 weeks after every dose increase. Women can discuss effective forms of birth control with their healthcare provider.

Like Saxenda and Wegovy, Zepbound has the same black box warning about thyroid tumors.

Note: Zepbound is the only tirzepatide drug FDA-approved for weight loss. Mounjaro contains tirzepatide and is FDA-approved for Type 2 diabetes but is commonly prescribed off-label for weight loss. Compounded tirzepatide drugs are not approved or regulated by the FDA.

Natural alternatives to phentermine

Many patients ask about natural alternatives to phentermine. The natural alternative aisle is filled with diet pills and weight loss supplements touting weight loss benefits and money-back guarantees. Ingredients like green coffee bean extract, green tea extract, guarana, vitamin b6, and cayenne pepper may sound harmless. However, long-term studies of natural supplements conclude that even though they are made with natural ingredients, they are not likely to contribute to significant weight loss—and, in some cases, may be harmful. Be cautious when supplement labels claim to boost energy, boost metabolism and increase fat burning and energy levels to stop weight gain and fat production. These claims are likely unfounded and do not mean they are natural phentermine alternatives or substitutes. FDA-approved over-the-counter phentermine alternatives and phentermine alternative supplements do not exist.

Also, supplements are not held to the same standards as prescription medications. The Dietary Supplement Health and Education Act (DSHEA) assigns responsibility to dietary supplement companies to ensure safety standards. The FDA does not have the authority to approve supplements for safety and efficacy before they are sold to the public. If you are considering taking a supplement to help with weight loss, consult your healthcare provider. Prescription weight loss medications are not studied in combination with supplements, so you should not use a supplement in combination with a prescription weight loss medication—unless advised by your healthcare professional. 

Consult your healthcare provider about dietary changes and exercise. Most healthcare providers recommend lifestyle changes along with prescription weight loss medication. A registered dietitian can be an excellent resource on your weight loss journey, helping you devise a personalized eating plan that considers your nutritional needs, calorie intake, medical conditions, and lifestyle. Diets are not a one-size-fits-all approach. The best eating plan is one that is healthy, with a variety of nutritious foods, and something you can stick to for the long term. 

Regarding exercise, adults should aim for at least 150 minutes of moderate-intensity activity per week to help decrease body fat, plus two days of muscle-strengthening activity to help build and maintain muscle mass. One way to attain the 150 minutes is to walk for 30 minutes a day, 5 days a week. A gym is not necessary—you can walk outside or choose from thousands of free YouTube videos—there are even free indoor walking videos online. Just check with your healthcare provider first to see if there are any limitations on physical activity before selecting an exercise plan. 

How to switch to a phentermine alternative

When considering a switch to a phentermine alternative:

  • Check your formulary, or ask your healthcare provider to check your formulary to see which phentermine alternatives your health insurance plan covers. You can also search the SingleCare website or mobile app for free coupons. SingleCare customers can save up to 80% on prescription prices—what’s more, you can use SingleCare savings every time you fill your prescription.
  • Consult your healthcare provider. Your healthcare provider is the only one who can determine which medication is best for you, considering your medical and family history, medical conditions, and medications you take that may potentially interact with weight-loss medications. You can also talk about dietary changes and exercise and ask for a referral to a registered dietitian.
  • Once the new prescription is sent to the pharmacy, speak with your pharmacist. Review dosing instructions and potential side effects, and ask any questions. If you get an injectable drug, be sure you understand how and when to use it, as well as how to store and dispose of it. 
  • When at home, read the prescription label, patient information leaflets, and/or medication guides. If anything concerns you or if you have questions, consult your healthcare provider or pharmacist.