Obesity has become a major health concern affecting almost half of the American population. According to the Centers for Disease Control and Prevention (CDC), 4 out of 10 people in the US are dealing with obesity. It is alarming that a recent study predicts that by 2030, nearly half of all US adults will be obese, including almost 1 in 4 who will have severe obesity. The obesity rate will exceed 50% in 29 states.

Living with obesity is tough. It makes you feel tired, affects your feelings about yourself, and stops you from doing things you love. It’s like carrying a heavy weight that you can’t put down. Every day is a struggle, and finding the right help can feel overwhelming.

In this article, we will explore two popular medications weight loss medications: Ozempic and Phentermine. You’ll learn about how they work, their benefits, costs, and any side effects.

So, let’s get started!

Key Takeaways

  • Ozempic (Semaglutide) and Phentermine are used for weight loss but work differently. Ozempic primarily serves as a diabetes medication that affects appetite and glucose metabolism, leading to weight loss. On the other hand, Phentermine is a short-term weight loss aid that suppresses appetite.
  • Ozempic is given via weekly injections, while Phentermine is taken orally. This difference in administration can influence a person’s preference or suitability for either medication based on their lifestyle, needle phobia, or convenience.
  • Ozempic has been associated with cardiovascular benefits in people with heart disease. In addition to its role in weight loss and diabetes management, Ozempic can also reduce the risk of heart attack and stroke, offering a dual benefit for some individuals.
  • Phentermine is intended for short-term use. Due to its nature and potential side effects, Phentermine is typically prescribed for a limited period to kickstart weight loss in conjunction with lifestyle changes.
  • Cost and accessibility vary between the two medications. Ozempic does not have a generic version and is available only by prescription as an injectable solution, which might affect its cost and accessibility. Phentermine, available in generic form and brand names, might be more accessible and affordable for some patients.

Comparing Ozempic vs Phentermine

Drug ClassGlucagon-like peptide-1 (GLP-1) receptor agonistsSympathomimetic Amine Anorectic
Indications and UsesType 2 diabetes mellitusWeight reduction
Limitations of UseNot recommended as first-line therapy for patients inadequately controlled on diet and exercise, has not been studied in patients with a history of pancreatitis, not for treatment of type 1 diabetes mellitusPhentermine should not be used by individuals with a history of heart disease, high blood pressure, or hyperthyroidism, It is not recommended for use in pregnant or breastfeeding women, Phentermine should not be used in combination with other weight loss medications or certain antidepressants.
Age Approval18 years old and older12 years or older who are obese
Dosage And AdministrationWeekly injectionDaily oral medication
Forms and StrengthsInjectable solution, 0.25 mg/0.5 mL, 0.5 mg/0.5 mL, 1 mg/0.5 mLCapsules:37.5 mg

Tablets: 37.5 mg

Side EffectsNausea, vomiting, diarrhea, abdominal pain, constipationCardiovascular palpitation, tachycardia, elevation of blood pressure, ischemic events, overstimulation, restlessness, dizziness, insomnia, euphoria, dysphoria, tremor, headache, psychosis, dryness of the mouth, unpleasant taste, diarrhea, constipation, other gastrointestinal disturbances, impotence and changes in libido
Warnings and PrecautionsRisk of Thyroid C-cell Tumors, pancreatitis, diabetic retinopathy complications, hypoglycemia with concomitant use of insulin secretagogues or insulin, acute kidney injury, hypersensitivityCoadministration with other drugs for weight loss is not recommended, rare cases of primary pulmonary hypertension have been reported
ContraindicationsPersonal or family history of medullary thyroid carcinoma (MTC), Multiple Endocrine Neoplasia syndrome type 2 (MEN 2), and hypersensitivity to semaglutide or any of the ingredients in OzempicHistory of cardiovascular disease (e.g., coronary artery disease, stroke, arrhythmias, congestive heart failure, uncontrolled hypertension), during or within 14 days following the administration of monoamine oxidase inhibitors, hyperthyroidism, glaucoma, agitated states, history of drug abuse, pregnancy, nursing, known hypersensitivity or idiosyncrasy to the sympathomimetic amines
Cost through US Pharmacies

1 pen: $947-$1014

  • (37.5mg) 30 Tablets:  $14.82-$17.31
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  • (37.5mg) 30 Capsule: $6.97-$17.55
  • (30 mg) 30 Capsule: $5.61-$19.89
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  • 1 pen: $429.96
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Currently Unavailable

What is Ozempic (semaglutide)?

Ozempic, with the active ingredient semaglutide, is a prescription medication primarily used to treat type 2 diabetes in adults. As a part of the drug class known as glucagon-like peptide-1 (GLP-1) receptor agonists, it mimics the effects of the GLP-1 hormone in the body. This hormone plays a crucial role in glucose metabolism by stimulating the pancreas to release insulin when blood sugar levels are high and lowering glucagon secretion, which otherwise raises blood sugar levels. By doing so, Ozempic helps manage blood sugar levels and is associated with lowering certain risks in people who have heart disease, including reducing the likelihood of heart attack and stroke.

In addition to its primary use in diabetes management, Ozempic is also known to be prescribed off-label for weight loss or weight management. Although not approved by the Food and Drug Administration (FDA) specifically for this purpose, its ability to decrease appetite and slow gastric emptying can contribute to weight loss, making it a tool for weight management in some instances.

Ozempic is only available through a prescription and is a liquid solution in prefilled, disposable injection pens. The medication is administered once a week by injection under the skin. Its availability is limited to this injectable form, and no generic version of Ozempic is on the market, highlighting its exclusivity and specificity in treatment protocols.

What is Phentermine?

Phentermine is a prescription medication primarily used as a short-term aid in weight loss. It is intended for use alongside a doctor-approved exercise, behavior change, and reduced-calorie diet program, specifically targeting overweight individuals, including those who are obese or have weight-related medical problems. Weight reduction can help lessen the many health risks associated with obesity, such as heart disease, diabetes, high blood pressure, and a potentially shorter lifespan.

The exact mechanism through which phentermine aids in weight loss is not fully understood. However, it works by decreasing appetite, increasing the body’s energy, or affecting certain brain parts. As an appetite suppressant, phentermine falls within the class of drugs known as sympathomimetic amines.

Phentermine is available under various brand names, including Adipex-P, Ionamin, and Pro-Fast, and in generic form, ensuring its accessibility to a wide range of individuals. It comes in several forms, including tablets and extended-release capsules taken orally. The dosage and form prescribed can vary based on individual medical conditions and response to treatment, with adjustments made by a healthcare provider to find the most effective dose.

Dosage And Administration


Start with a 0.25 mg subcutaneous injection once weekly for 4 weeks. This dose is intended for treatment initiation and is not effective for glycemic control on its own. After the initial 4 weeks, increase the dosage to 0.5 mg once weekly. Depending on the individual patient’s glycemic response and tolerability, the dosage may be further increased to 1 mg once weekly.


Dosage should be individualized to obtain an adequate response with the lowest effective dose. The usual adult dose is one capsule (37.5 mg) daily, administered before breakfast or 1 to 2 hours after breakfast for appetite control. Alternatively, some patients may find a half tablet (18.75 mg) daily adequate, or it may be desirable to give half tablets (18.75 mg) two times a day. The dosage may be adjusted to the patient’s needs. Late evening administration should be avoided due to the risk of insomnia.

Warnings and Precautions


  • Risk of Thyroid C-cell Tumors
  • Pancreatitis
  • Diabetic Retinopathy Complications
  • Hypoglycemia with Concomitant Use of Insulin Secretagogues or Insulin
  • Acute Kidney Injury
  • Hypersensitivity


  • Serious regurgitant cardiac valvular disease
  • Tolerance to the anorectic effect usually develops within a few weeks
  • Phentermine may impair the ability to engage in potentially hazardous activities such as operating machinery or driving a motor vehicle
  • Risk of abuse and dependence
  • Concomitant alcohol use may result in an adverse drug reaction
  • Use caution in patients with even mild hypertension
  • A reduction in dose of insulin or oral hypoglycemic medication may be required in some patients
  • Late evening administration should be avoided (risk of resulting insomnia)
  • Withdrawal effects following prolonged high dosage administration
  • Use caution when administering phentermine to patients with renal impairment
  • Phentermine is not recommended for use in pediatric patients ? 16 years of age
  • Development of primary pulmonary hypertension
  • Development of serious valvular heart disease
  • The risk of an increase in blood pressure

Did You Know?

Healthcare providers wrote over 9 million prescriptions for Ozempic and similar drugs in the last quarter of 2022. These drugs have become popular due to their weight-loss effects, and it is estimated that in the next 10 years, around 7% of the US population, which is 24 million people, could be using them.

How Effective are Ozempic and Phentermine for Weight Loss?


A study showed that people who used Ozempic lost around 5.9% of their total body weight after 3 months and roughly 10.9% after 6 months. This means that if someone weighed 200 pounds, they might lose about 12 pounds in 3 months and 22 pounds in 6 months on Ozempic. The study also revealed that those without type 2 diabetes saw more weight loss compared to those with diabetes.

For instance, people without diabetes lost about 6.3% of their weight in 3 months, whereas those with diabetes lost about 3.9%. By 6 months, the difference became more prominent, with non-diabetics losing about 11.8% of their weight and diabetics around 7.2%. This suggests that Ozempic can be a helpful tool for weight management in both groups, although people without diabetes might see slightly better results.

Another study published in the New England Journal of Medicine involved 1961 adults without diabetes but with overweight or obesity. The participants were given either Ozempic or a placebo once a week for 68 weeks along with lifestyle interventions such as diet and exercise.

Those who took Ozempic lost significantly more weight than those who received the placebo. Specifically, the average weight loss in Ozempics was about 14.9% of the participant’s body weight, compared to just 2.4% with the placebo.

This means that, on average, people taking Ozempic lost almost 15% of their starting weight. A higher number of participants who received Ozempic also achieved weight reductions of 5% or more (86.4% of participants), 10% or more (69.1%), and 15% or more (50.5%), compared to those who took the placebo.


Phentermine has also been proven highly effective for weight loss in a study that included 795 patients with obesity. Out of all the participants, 45.6% (about 324 people) were able to lose at least 5% of their body weight after taking Phentermine. On average, individuals lost around 3.8 kilograms (8.4 pounds). This implies that nearly half of the people who took Phentermine saw a noticeable decrease in their weight.

Another study showed promising results for Phentermine. The research involved 13,972 adults who started taking Phentermine, and those who used it for more than 12 months experienced significant weight loss compared to those who took it for 3 months or less.

By the 24-month, long-term users lost about 7.4% more of their body weight. Even more encouraging, this greater weight loss did not come with an increased risk of cardiovascular disease or death, which were rare outcomes in the study. In simpler terms, Phentermine, when used for a longer period, helped people lose more weight without raising their risk of heart issues or dying.

The study provides a solid argument for considering Phentermine as a long-term treatment option for obesity, especially since lifestyle changes alone often don’t lead to significant or lasting weight reduction for many people.


Buy Canadian Insulin offers a cost-effective solution for those who want to use Ozempic (Semaglutide) to aid their weight loss journey. Prices start from $429.69 for a single injection pen, and purchasing includes reliable express shipping and easy ordering. This makes it an excellent choice for affordable and convenient weight management.


When comparing Ozempic and Phentermine for weight loss, each medication presents distinct benefits depending on individual health profiles and weight loss goals. Ozempic, primarily used for diabetes management, offers additional cardiovascular benefits and effective long-term weight management, making it suitable for patients with or at risk of heart disease. Conversely, Phentermine, used as a short-term weight loss solution, is ideal for rapid weight loss initiation, particularly in individuals without significant comorbid conditions but requires careful monitoring due to potential cardiovascular side effects.

Ultimately, healthcare professionals should guide the choice between Ozempic and Phentermine based on an individual’s specific health needs, potential side effects, and the sustainability of the weight loss method. As the obesity epidemic continues to challenge public health, effective use of these medications in conjunction with lifestyle changes can be a critical component of a comprehensive weight management strategy.

FAQs About Phentermine And Ozempic

Which is better for weight loss, Ozempic or Phentermine?

Both offer effective weight loss solutions, but their suitability depends on individual health conditions and weight loss goals. Ozempic is preferred for long-term weight management and those with or at risk of heart disease, while Phentermine is effective for short-term weight loss efforts.

How do I choose between Ozempic and Phentermine for weight loss?

When choosing between Ozempic and Phentermine for weight loss, it is important to consider your health needs and discuss them with your healthcare provider. The decision between Ozempic and Phentermine should be based on your health conditions, preferences, and goals.

What alternative medications are available for Ozempic?

What alternative medications are available for Phentermine?

  • Tirzepatide (Mounjaro)
  • Alli (orlistat)
  • Liraglutide (Saxenda)
  • Bupropion-naltrexone

Can you take phentermine and Ozempic (semaglutide) together for weight loss?

Phentermine and Semaglutide are effective in aiding weight loss, and some individuals may experience a faster reduction in excess weight by taking them together. Combining these two medications can reduce appetite, as Phentermine and Semaglutide help curb hunger.

What is safer phentermine or Ozempic (semaglutide)?

If you are looking for a safer option between Ozempic (semaglutide) and Phentermine, it largely depends on your body mass index (BMI) and other health conditions. For instance, individuals with a BMI of 30 or higher should take Phentermine to lose weight. On the other hand, Semaglutide may be a better option for those with a BMI of 27 or higher and other health concerns such as high blood pressure or type 2 diabetes.

Does Ozempic cause facial sagging?

Some individuals who use the diabetes medication Ozempic off-label for weight loss have experienced “Ozempic face” as a side effect of rapid weight loss, resulting in sagging facial skin and an aged appearance.

Is phentermine safe for everyone?

Although phentermine is a commonly prescribed weight-loss medication, it is not suitable for individuals with heart conditions, high blood pressure, an overactive thyroid, or glaucoma. It is also not recommended for pregnant or breastfeeding women.

Does Ozempic alter body fat distribution?

While Ozempic has shown effectiveness in weight management, some users have noticed unintended changes in their body fat distribution. A common side effect is reducing fat in specific areas such as the buttocks, leading to changes in size and shape.

Should phentermine be taken long-term?

Phentermine is typically prescribed for short-term use to kickstart weight loss efforts, usually up to 12 weeks. It should be complemented with a proper diet and exercise regimen. Adhering to the prescribed dosage is crucial to avoid potential side effects and dependency.

Why do I still feel hungry on phentermine?

Some individuals may experience increased hunger around 3-4 months due to deviating from their diet and consuming appetite-stimulating foods. While phentermine continues to work, consuming the wrong foods can trigger hunger more than the medication can suppress it.

Can phentermine 37.5 mg be taken twice daily?

Phentermine tablets (37.5 mg) are typically taken once daily, before or after breakfast. Depending on circumstances, the dosage may be adjusted to 18.75 mg (half tablet) once or twice daily.

Will weight return after stopping phentermine?

Limited data supports the efficacy of phentermine, with only three placebo-controlled trials conducted to date. While participants initially experience weight loss, it is often short-lived, with one-third regaining lost weight within a year of discontinuing treatment.

Is it safe to consume coffee while on phentermine?

Consumers should limit their caffeine intake (e.g., coffee, tea, cola, chocolate, herbal supplements) while using phentermine. It is advisable to avoid additional caffeine-containing medications whenever possible, as excessive caffeine consumption can exacerbate side effects of phentermine.

Related Articles:

If you want to learn more about weight loss medications, read some of our articles:


Elsevier B.V. (2024). Phentermine – an overview. ScienceDirect Topics. Retrieved April 10, 2024, from https://www.sciencedirect.com/topics/medicine-and-dentistry/phentermine

Novo Nordisk. (2017). Highlights of Prescribing Information for Ozempic (semaglutide) injection. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/209637lbl.pdf

Wilding, J. P. H., Batterham, R. L., Calanna, S., Davies, M., Van Gaal, L. F., Lingvay, I., & STEP 1 Study Group*. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine, 384(11), 989-1002https://www.nejm.org/doi/full/10.1056/NEJMoa2032183

Lewis, K. H., Fischer, H., Ard, J., Barton, L., & colleagues. (2019). Safety and effectiveness of longer-term phentermine use: Clinical outcomes from an electronic health record cohort. Obesity, 27(4), 591-602. Retrieved from https://onlinelibrary.wiley.com/doi/10.1002/oby.22430

Kim, H. O., Lee, J. A., Suh, H. W., Kim, Y. S., Kim, B. S., Ahn, E. S., … Park, Y. G. (2013). Postmarketing Surveillance Study of the Efficacy and Safety of Phentermine in Patients with Obesity. Korean Journal of Family Medicine, 34(5), 298–306.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3791337/

Ghusn, W., De la Rosa, A., Sacoto, D., et al. (2022, September 19). Weight Loss Outcomes Associated With Semaglutide Treatment for Patients With Overweight or Obesity. JAMA Network Open, 5(9), e2231982. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2796491