Mounjaro vs. Adipex
See how Mounjaro and Adipex compare on approved uses, dosing, side effects, and cost.
Key Takeaways
Mounjaro is an injectable dual GIP/GLP-1 agonist approved for type 2 diabetes, while Adipex is an oral stimulant approved only for short-term weight loss.
Mounjaro follows a 21-week dose titration schedule, while Adipex is prescribed at a fixed dose from the first day of treatment.
Adipex is a Schedule IV controlled substance with abuse potential, while Mounjaro carries a boxed warning for thyroid C-cell tumors seen in animal studies.
Mounjaro vs. Adipex Drug Summary
Mounjaro
Mounjaro (tirzepatide) is a dual GIP/GLP-1 receptor agonist FDA-approved to control blood sugar in adults and children 10 and older with type 2 diabetes. It is given as a once-weekly subcutaneous injection with a dose that increases every four weeks. It is also used off-label for weight loss in people without diabetes.
Adipex
Adipex (phentermine) is a sympathomimetic stimulant FDA-approved as a short-term adjunct to diet and exercise for weight loss in obesity. It is taken orally, usually once daily, and is not intended for long-term use. It has been prescribed since 1959 and remains one of the most widely used weight-loss medications in the U.S.
Mounjaro vs. Adipex Side Effects
Mounjaro
Adipex
Mounjaro vs. Adipex Dosage
Mounjaro
Adipex
| STAGE | DOSE | WHEN |
| Starting dose | 2.5 mg once weekly | Weeks 1-4 |
| Maximum dose | 15 mg once weekly | Week 21 onward |
| Dose changes | 5 increases | Every 4 weeks |
| STAGE | DOSE | WHEN |
| Starting dose | 15 mg once daily | At the start |
| Maximum dose | 15 mg once daily | Same as starting |
| Dose changes | None | Fixed dose |
Mounjaro
| STAGE | DOSE | WHEN |
| Starting dose | 2.5 mg once weekly | Weeks 1-4 |
| Maximum dose | 15 mg once weekly | Week 21 onward |
| Dose changes | 5 increases | Every 4 weeks |
Adipex
| STAGE | DOSE | WHEN |
| Starting dose | 15 mg once daily | At the start |
| Maximum dose | 15 mg once daily | Same as starting |
| Dose changes | None | Fixed dose |
Mounjaro vs. Adipex Indications
Mounjaro
Mounjaro is FDA-approved to improve blood sugar control in adults and in children 10 and older with type 2 diabetes, used alongside diet and exercise. It is not approved for type 1 diabetes. Many prescribers also use it off-label for weight loss in patients without diabetes.
Type 2 diabetes blood sugar control in adults
Type 2 diabetes blood sugar control in children 10+
Off-label: weight loss in people without diabetes
Adipex
Adipex is FDA-approved only as a short-term adjunct to diet and exercise for weight loss in people with obesity. It is not approved for long-term or chronic weight management. It is also not approved for use in patients 16 and younger.
Short-term adjunct to diet and exercise for obesity
Not approved for long-term weight management
Not approved for patients 16 and younger
Mounjaro vs. Adipex Pros and Cons
Mounjaro
Mounjaro offers strong blood sugar control plus significant weight loss in clinical trials, with the convenience of a once-weekly injection. It is a newer, brand-name biologic, so it typically costs more and is not always covered by insurance for off-label weight loss use.
Pros
FDA-approved specifically for type 2 diabetes management
Only needs to be injected once a week
Substantial weight loss demonstrated in clinical trials
No known abuse or dependence potential
Cons
Roughly $1,000 to $1,300 per month without insurance
Requires a subcutaneous injection rather than a pill
Boxed warning for thyroid C-cell tumor risk
GI side effects like nausea and diarrhea are common
Adipex
Adipex is an inexpensive, well-established oral option for short-term weight loss support. Because it is a stimulant and a controlled substance, it carries cardiovascular and dependence risks that limit it to brief use.
Pros
Roughly $50 to $150 per month, far cheaper than Mounjaro
Taken as a pill, no injections needed
Decades of clinical use and prescribing experience
Once-daily oral dosing fits easily into routines
Cons
Only approved for a few weeks of use, not long-term
Schedule IV controlled substance with abuse potential
Contraindicated with heart disease or uncontrolled hypertension
Cannot be combined with MAOIs due to hypertensive crisis risk
Common Symptoms and Related Diseases You Can Explore
Explore a range of common symptoms the Doctronic Symptom Checker can help you understand.