Which is more effective for weight loss: Ozempic or Contrave?

Ozempic is more effective. Ozempic causes 15–18% weight loss; Contrave causes 5–10% weight loss. Ozempic works faster and produces greater absolute weight loss. However, Contrave is an oral pill (no injections) and works for some people who don't respond to or can't tolerate GLP-1s.

What is the mechanism of action difference?

Ozempic (semaglutide) is a GLP-1 receptor agonist. It directly suppresses appetite by activating brain hunger centers and slowing stomach emptying. Contrave combines naltrexone (opioid antagonist) and bupropion (antidepressant) to modulate appetite and energy. Different mechanisms; GLP-1 is more direct and potent.

Is Contrave safe if I don't have depression?

Yes, Contrave is safe for weight loss in non-depressed patients. Bupropion is used in Contrave at lower doses than psychiatric doses. Common side effects: nausea, constipation, insomnia. Contraindicated in seizure disorders. Generally well-tolerated for weight loss.

Which has fewer side effects?

Contrave side effects are generally milder: nausea (30%), constipation (20%), insomnia (10%). Ozempic side effects are more common: nausea (70%), constipation (23%), but similar rates. Ozempic nausea is more prominent but typically resolves. Contrave requires 4 pills daily; Ozempic is 1 weekly injection.

What is the cost difference?

Contrave: $200–$300/month (copay with insurance) or $250–$400 retail. Ozempic: $890–$1,200/month retail, or $25–$100 with insurance. Contrave is significantly cheaper, especially without insurance. Cost is a major advantage of Contrave.

Who should choose Contrave vs Ozempic?

Choose Contrave if: you want an oral medication, can't tolerate injections, cost is a major concern, or mild weight loss is acceptable. Choose Ozempic if: you want maximum weight loss, don't mind injections, have cardiovascular disease or kidney disease (additional benefits), or have failed other weight loss medications.

Ozempic vs Contrave: Complete Mechanism & Weight Loss Comparison

Two very different weight loss medications. Ozempic (GLP-1) and Contrave (naltrexone/bupropion) use different mechanisms. Here's the complete comparison: efficacy, side effects, cost, and who should use each.

Mechanism of Action: How They Work Differently

Ozempic (Semaglutide): Direct Appetite Suppression

Ozempic is a GLP-1 receptor agonist. It mimics glucagon-like peptide-1, a natural hormone that regulates appetite.

How it works:

Activates GLP-1 receptors in the brain (hypothalamus, brainstem) that suppress hunger
Slows gastric emptying (food stays in stomach longer) creating fullness
Increases satiety (feeling satisfied with less food)
Reduces cravings and food intake automatically
Effects are immediate (within hours to days)

Result: You simply eat less and feel full quickly. Appetite is genuinely suppressed.

Contrave (Naltrexone/Bupropion): Multi-Target Approach

Contrave combines two existing drugs in a specific ratio:

Naltrexone (opioid antagonist): Blocks opioid receptors in the brain, particularly the hypothalamus. This blocks feedback that suppresses appetite. By blocking this feedback, the body thinks it's in a caloric deficit and reduces hunger slightly.

Bupropion (antidepressant/stimulant): An atypical antidepressant that increases dopamine and norepinephrine. Enhances energy, mood, and may directly suppress appetite.

Combination effect: Synergistic. Naltrexone sensitizes the brain to bupropion's effects, enhancing appetite suppression beyond either drug alone.

Result: Modest appetite suppression (less direct than GLP-1), improved energy and mood, slower weight loss onset.

Weight Loss Efficacy: Side-by-Side Comparison

Metric	Ozempic (Semaglutide)	Contrave (Naltrexone/Bupropion)
Average weight loss	15–18% body weight (STEP trials)	5–10% body weight (COR trials)
For 200 lb person	30–36 lbs	10–20 lbs
Trial duration	68 weeks	52–56 weeks
Weight loss onset	2–4 weeks	4–8 weeks
Peak efficacy	8–12 weeks (full dose reached)	16–24 weeks
Responder rate (≥5% weight loss)	85–90%	50–60%
Non-responder rate	10–15% lose <5%	40–50% lose <5%

Practical meaning: Ozempic is significantly more effective. Most people lose meaningful weight with Ozempic; many lose little weight with Contrave.

Side Effects Comparison

Side Effect	Ozempic	Contrave	Severity
Nausea	70%	30%	Ozempic worse
Vomiting	5–10%	1–2%	Ozempic worse
Constipation	23%	20%	Similar
Insomnia	5%	10–15%	Contrave worse
Dry mouth	3%	15%	Contrave worse
Headache	8%	15%	Contrave worse
Jitteriness/Anxiety	2%	8–12% (bupropion effect)	Contrave worse

Summary: Ozempic has more GI side effects (nausea/vomiting). Contrave has more CNS side effects (insomnia, anxiety, headache). Neither is side-effect-free.

Dosing and Administration

Ozempic (semaglutide injection):

Once-weekly subcutaneous injection
Starting dose: 0.25 mg, titrating to 2.4 mg weekly
Takes 16 weeks to reach full dose
Simple administration; self-injected at home

Contrave (naltrexone/bupropion oral):

Oral tablets, four times daily (morning, midday, evening, bedtime)
Starting dose: 1 tablet twice daily, titrating to 2 tablets twice daily
Takes 4 weeks to reach full dose
Must remember to take 4 pills daily

Convenience winner: Ozempic (once weekly vs. four times daily).

Cost Comparison

Medication	Retail Cost	Insurance Copay	Annual Cost (retail)
Ozempic	$890–$1,200/month	$25–$100/month	$10,800–$14,400
Contrave	$250–$400/month	$30–$75/month	$3,000–$4,800

Cost winner: Contrave by a large margin. About 1/3 the cost of Ozempic retail and similarly cheaper with insurance.

Who Should Use Ozempic vs Contrave?

Choose Ozempic If You:

Want maximum weight loss (15–18% average)
Don't mind weekly injections
Have type 2 diabetes (dual benefit for blood sugar control)
Have cardiovascular disease or kidney disease (additional health benefits)
Failed Contrave or other oral medications
Can afford the cost ($900–$1,500/month) or have good insurance coverage
Can tolerate GI side effects (nausea, constipation)

Choose Contrave If You:

Want an oral medication (no injections)
Cost is a major concern ($250–$400/month)
Modest weight loss is acceptable (5–10%)
Can't tolerate GLP-1 nausea
Have depression or mood issues (bupropion helps both)
Prefer better energy and mood (bupropion effect)
Don't mind taking 4 pills daily

Medical Considerations & Contraindications

Ozempic (Semaglutide):

Avoid: Personal or family history of medullary thyroid cancer, MEN2 syndrome, pregnancy
Use cautiously: History of pancreatitis, severe kidney disease
Safe in: Diabetes, cardiovascular disease, kidney disease (beneficial)

Contrave (Naltrexone/Bupropion):

Avoid: Seizure disorder (bupropion lowers seizure threshold), opioid dependence, severe liver disease
Use cautiously: History of depression or bipolar disorder (bupropion may worsen), high blood pressure (may increase BP slightly)
Safe in: Most conditions; good alternative to GLP-1s

Can You Use Both Ozempic and Contrave?

Not typically recommended. Combination increases side effects (nausea, constipation, anxiety) without clear additional benefit. Ozempic alone is more effective than either drug alone, so combination with Contrave is rarely used.