acarbose vs phentermine
Side-by-side comparison of acarbose and phentermine Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.
Precose
Adipex-P, Lomaira
Acarbose is a medicine that helps lower blood sugar levels in people with type 2 diabetes. It works best when used with diet and exercise.
Phentermine is a drug that can help you lose weight. It works by reducing your appetite.
Acarbose is used to help control blood sugar in adults with type 2 diabetes. You should use it along with a healthy diet and regular exercise. This medicine helps to keep your blood sugar from getting too high after you eat.
Phentermine is used for a few weeks to help with weight loss. It is for people with a body mass index (BMI) of 30 or more. It is also for people with a BMI of 27 or more who have other health risks like high blood pressure, diabetes, or high cholesterol.
Acarbose slows down the digestion of carbohydrates (sugars and starches) in your body. It does this by blocking certain enzymes in your small intestine that break down carbs. This helps to prevent a sharp rise in blood sugar after meals.
Phentermine is a stimulant that affects your brain. It helps to decrease your appetite. This can help you eat less and lose weight.
- • Gas
- • Diarrhea
- • Abdominal pain
- • Dry mouth
- • Difficulty sleeping
- • Constipation
- Low blood sugar 269
- Feeling sick to your stomach 203
- High blood sugar 200
- Feeling lightheaded 160
- Loose, watery stools 147
- Drug not working 537
- Feeling sick to your stomach 475
- Aches 462
- Feeling tired 346
- Head pain 335
You should not take acarbose if you have diabetic ketoacidosis or cirrhosis. Also, do not take it if you have inflammatory bowel disease, colon ulcers, or any bowel obstruction. This medicine can cause liver problems in some people. Tell your doctor right away if you develop symptoms like yellowing of the skin or eyes.
Taking phentermine with other weight loss drugs is not recommended. In rare cases, people have developed lung problems called pulmonary hypertension. Tell your doctor right away if you have shortness of breath, chest pain, fainting, or swelling in your legs. Phentermine can be habit-forming, so use it carefully.
Talk to your doctor if you are pregnant or plan to become pregnant. It is not known if acarbose will harm your unborn baby. Talk to your doctor if you are breastfeeding or plan to breastfeed. It is not known if acarbose passes into breast milk.
Do not take phentermine if you are pregnant. Weight loss during pregnancy can harm the baby. Talk to your doctor about safe ways to manage your weight if you are pregnant or plan to become pregnant.
Also Compare — Nearby Drugs
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How to Read This acarbose vs phentermine Comparison
acarbose is classified in the Alpha-Glucosidase Inhibitor drug class, while phentermine sits within the Sympathomimetic Amine (Appetite Suppressant) class. Drugs from different classes work through distinct mechanisms, so a head-to-head comparison illustrates trade-offs rather than equivalence. Both drugs are prescription-only, so a licensed provider must authorize use.
Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, acarbose has 979 submissions while phentermine has 2,155. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.
A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between acarbose and phentermine — always consult your physician or pharmacist first.
Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.