Wegovy and phentermine are two weight loss medications offering different mechanisms to help people achieve their weight loss goals. Wegovy, a newer option, has gained attention for its effectiveness in supporting long-term weight management, while phentermine has been around for decades as a short-term option for weight loss.
While both medications are prescribed for weight loss, they’re quite different. They differ in dosages, cost, potential side effects, and active ingredients. Deciding which one to choose depends on personal weight loss needs, health profiles, and your healthcare provider’s recommendations.
Read on to understand the key differences between Wegovy and phentermine so you can choose the best option for your needs.
What Is Wegovy?
Wegovy is a once-weekly injectable medication prescribed to people with obesity or overweight who have weight-related health conditions. Its active ingredient, semaglutide, is a GLP-1 (glucagon-like peptide-1) receptor agonist. Semaglutide mimics GLP-1, a hormone that helps regulate appetite, slow digestion, and increase feelings of fullness after eating. Combined with reduced calorie intake and exercise, these effects can help you lose weight.
Semaglutide is also an active ingredient in Ozempic, a similar medication prescribed to manage blood sugar levels in people with type 2 diabetes.
Wegovy was approved by the FDA (US Foods and Drug Administration) in 2021 for long-term weight management in adults with a BMI of 30 or higher or a BMI of 27 or higher with at least one weight-related medical condition, such as hypertension, type 2 diabetes, or high cholesterol.
What Is Phentermine?
Phentermine is a prescription medication that was approved by the FDA in 1959 for short-term weight loss for people with obesity or overweight. It works as an appetite suppressant and is prescribed along with a reduced-calorie diet and increased physical activity. Phentermine is still one of the most prescribed weight loss medications today. Phentermine works by stimulating the central nervous system, which increases heart rate and blood pressure, which in turn decreases appetite.
Specifically, it targets neurotransmitters in the brain, including norepinephrine, which helps to signal feelings of fullness and reduce food noise, which makes you think about food throughout the day.
Wegovy vs. Phentermine: What Is the Difference?
The key difference between Wegovy and phentermine is in their mechanism of action and active ingredients. Wegovy contains semaglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist. It works by mimicking a GLP-1 hormone in the body that regulates appetite. It slows digestion, helps control blood sugar, and reduces hunger signals, lowering calorie intake.
Phentermine, on the other hand, is an appetite suppressant that affects the central nervous system. It’s a stimulant that increases the release of certain neurotransmitters, such as dopamine and norepinephrine, which help reduce hunger. However, because of its stimulant effects, phentermine is approved for use for only 12 weeks, but your doctor can prescribe it off-label for longer use.
Wegovy vs. Phentermine: Which Is More Effective?
Both Wegovy and phentermine have been studied and proven effective for weight loss. While their effectiveness varies based on individual needs and goals, research shows that Wegovy is more effective than phentermine. In clinical trials, patients using Wegovy lost an average of 15% of their body weight over a year. Phentermine-topiramate was shown to have an average weight loss of around 5–10% of body weight over 6 months.
Both drugs improved vital health indicators like blood pressure and glucose levels.
According to one assessment, Wegovy can cause substantial body weight loss, much like gastric bypass surgery. On the other hand, older medications like phentermine usually cause less significant weight loss. However, the higher cost and shortages of more recent medications like Wegovy can be challenging.
Wegovy vs. Phentermine: Dose and Administration
Other major differences between Wegovy and phentermine are their dosing frequencies and how they’re taken. Here’s how they compare in dosages, form, and administration.
Dose and form
Wegovy is available as a pre-filled injectable pen containing semaglutide, administered once weekly. The dose is gradually increased over several months to help the body adjust and reduce side effects. The typical starting dose is 0.25 mg per week for 4 weeks. If your body tolerates the medication well, the dose is increased gradually every 4 weeks to a maintenance dose of 2.4 mg weekly.
Phentermine is taken orally in pill or capsule form, usually once daily before breakfast or 1 to 2 hours after breakfast. It also comes as an orally disintegrating tablet (ODT) that dissolves on the tongue. The dosage typically ranges from 15 to 30 mg and 37.5 mg daily.
It also has a low-dose 8 mg pill, Lomaira, taken 3 times a day, 30 minutes before meals.
Unlike Wegovy, phentermine doesn’t require gradual dose adjustments and is intended for short-term use, usually no longer than 12 weeks.
Administration method
Since Wegovy is a weekly injection, you can safely inject your dose at home subcutaneously (under the skin) in areas such as the stomach, thigh, or upper arm. You should follow a specific injection schedule, with each dose given on the same day each week. It’s also important to change injection sites with every dose to avoid injection site reactions.
Phentermine is taken orally once daily before breakfast or 1 to 2 hours after breakfast to avoid disrupting sleep because of its stimulant effects. Lomaira is taken 3 times daily in smaller doses of 8 mg, 30 minutes before meals.
Duration of treatment
Wegovy is approved for long-term use. If your body tolerates it well and it’s effective in helping you achieve your weight loss goals, you can continue taking it for chronic weight management in combination with diet and exercise.
Phentermine is only approved for short-term use, 12 weeks. However, your healthcare provider can prescribe it for longer use, usually intermittently, depending on how your body responds.
What Are the Side Effects of Wegovy vs. Phentermine?
Wegovy and phentermine have different mechanisms of action, so their side effects also differ. The common side effects of Wegovy are gastrointestinal, while phentermine’s are typically neurological (affecting the brain and nerves) or cardiac (affecting the heart).
Wegovy’s side effects are often worse when starting with the medication and during dose increase, but they disappear as your body adjusts to the medication. In contrast, phentermine’s side effects may last as long as you take it and get worse with time.
The most common side effects of Wegovy include:
- Nausea
- Diarrhea
- Constipation
- Vomiting
- Fatigue
- Abdominal pain
- Headache
- Dizziness
- Heartburn
- Gas
While rare, Wegovy has been associated with other serious side effects, which include:
- Pancreatitis-inflammation of the pancreas
- Gallbladder issues like gallstones
- Kidney problems
- Hypoglycemia
- rapid heartbeat
Like other GLP-1 medications, Wegovy comes with a boxed warning because of the risk of thyroid C-cell tumors, observed in animal studies. While it’s unknown whether Wegovy increases the risk of these tumors in humans, people with a personal or family history of multiple endocrine neoplasia syndrome type 2 (MEN 2) or medullary thyroid carcinoma should avoid this medication.
Consult your healthcare provider if you experience severe or persistent symptoms.
Common side effects of phentermine include:
- Increased heart rate
- Insomnia
- Dry mouth
- Anxiety or restlessness
- Constipation
- Unpleasant taste
- Diarrhea
- Dizziness
Rare but severe side effects of phentermine include valvular heart disease, withdrawal symptoms, and primary pulmonary hypertension.
Can You Switch from Phentermine to Wegovy (or Vice Versa)?
Yes, you can switch from phentermine to Wegovy. If you’re on phentermine and the side effects are intolerable, your weight loss has plateaued, or you just need a long-term option, transitioning to Wegovy may be a viable option. Wegovy is approved for long-term weight management and is designed to help with appetite control for a long time.
On the other hand, switching to phentermine can be an option if you’re currently taking Wegovy but are not seeing the desired weight loss results or are experiencing severe side effects or semaglutide shortage.
In either situation, it’s important to consult with a healthcare professional before switching these medications. Your doctor will evaluate your overall health, weight progress, and medical conditions to determine the best action.
Where Can I Buy Wegovy or Phentermine in Oklahoma?
Wegovy and Phentermine are prescription medications, meaning they’re only available through a licensed healthcare provider.
You can find Wegovy or phentermine in Oklahoma’s specialized weight loss clinics, such as NP2GO. At NP2GO, we provide personalized consultations to determine the best approach for each individual’s needs. Phentermine, being a controlled substance, requires at least one annual in-person visit to be prescribed, while Wegovy can often be managed through telehealth services. The follow-up phentermine visits are done virtually.
If you’re looking for Wegovy, telehealth services like NP2GO’s virtual weight loss visits allow patients in Oklahoma to consult with healthcare providers remotely.
Once Wegovy or phentermine is prescribed, we can send it straight to your door or the pharmacy of your choice.
Wegovy vs. Phentermine: Which Option Is Right for You?
Choosing between Wegovy and phentermine as a weight loss solution depends on several personal factors, including your health history, weight loss goals, cost, side effects, and treatment goals. Both medications can be effective but work differently and serve distinct purposes.
Wegovy may be a good option if you’re looking for long-term weight management support. Wegovy can also help you if you’re managing weight-related health issues like type 2 diabetes or high blood pressure. Its active ingredient, semaglutide, has been shown to help treat type 2 diabetes, cardiovascular problems, stroke, and heart attack. Wegovy is also a great choice if you struggle to remember daily pills. It offers a simple routine with only a once-weekly injection.
Phentermine, on the other hand, is usually prescribed for short-term weight loss and can be helpful for you if you’re looking to kickstart your weight loss journey over a few weeks or months. You can also choose phentermine if you’re on a budget. Phentermine is more affordable than Wegovy, which can be expensive. Phentermine may also be a suitable semaglutide alternative, especially when Wegovy is in short supply.
Additionally, if you prefer oral medications over injections, Phentermine’s tablet form may be more convenient and comfortable for daily use.
Having said that, choosing Wegovy or phentermine should involve thoroughly discussing with your healthcare provider. They can evaluate your health profile, review potential side effects, and match the treatment plan with your weight loss goals.
Wegovy vs. Phentermine: How Do They Compare?
Here’s a summary table highlighting key differences and similarities between Wegovy and Phentermine:
| Feature | Wegovy (Semaglutide) | Phentermine |
|---|---|---|
| Classification | GLP-1 receptor agonist | Stimulant |
| Administration | Subcutaneous injection (once weekly) | Oral tablet Oral capsule Extended-release capsule Orally disintegrating tablet |
| Dosage | Starting at 0.25 mg, increased every 4 weeks to 2.4 mg weekly | 15 mg to 37.5 mg daily |
| Mechanism of action | Mimics GLP-1 to regulate appetite and blood sugar | Increases neurotransmitters to suppress appetite |
| FDA ppproval | Long-term weight management Reduced risk of cardiovascular disease, stroke, and heart attack in adults with heart disease and obesity or overweight | Short-term weight loss |
| Common side effects | Nausea, vomiting, diarrhea, headache | Increased heart rate, insomnia, dry mouth |
| Long-term use | Approved for long-term use | Short-term use, up to 12 weeks at a time |
| Cost | Higher cost (may vary by insurance) | Generally lower cost |
| Best for | People with obesity and related health issues | Short-term weight loss jumpstart |
FAQ About Wegovy Vs. Phentermine
Can you take Wegovy and phentermine together?
While phentermine and Wegovy are medications that promote weight loss, the effects of using them together have not been thoroughly studied. Combining medications without research supporting their safety can increase the risk of side effects.
If you don’t achieve the desired results with one of these medications, your doctor may recommend switching between them. If they prescribe both simultaneously, paying close attention to their instructions and medical advice is important.
What is the difference between phentermine and semaglutide?
The key difference between phentermine and semaglutide is their mechanism of action. Phentermine is a stimulant that increases neurotransmitter levels to suppress appetite, while semaglutide mimics GLP-1, a hormone that helps regulate appetite and glucose. Each medication also has unique dosing and side effects.
Is there a more effective weight loss drug than Wegovy?
While Wegovy (semaglutide) is among the most effective FDA-approved weight loss drugs, new medications like tirzepatide (Zepbound, Mounjaro) have shown promising results. Others, like Retatrutide, may soon gain FDA approval and could potentially offer even greater benefits.
Zepbound, known for its dual action on GLP-1 and GIP receptors, has shown impressive weight loss outcomes in clinical trials. Retatrutide, which acts on multiple hormone receptors, is also being studied for its weight loss potential and could offer a broader metabolic impact.
Get a Wegovy or Phentermine Prescription in Oklahoma
If you’ve chosen Wegovy or Phentermine or are considering switching medications, we’re here to help you find the right solution. At NP2GO, we can assess your health profile, discuss your weight loss goals, and determine whether Wegovy or Phentermine best fits you. Whether you’re looking for the long-term support of Wegovy or the short-term boost that phentermine offers, our professional guidance ensures safe and effective treatment.
As the best weight loss provider in Oklahoma, we pride ourselves on offering accessible telehealth consultations and in-office visits, making it easy for you to discuss your treatment options. If you’re already on a weight loss medication but seeking a more effective alternative, we can help you explore your options. Reach out today to learn how we can support your weight loss journey and take the next step toward achieving your goals confidently.