Do I have to inject myself?

Yes — tirzepatide is a once-weekly injection given under the skin. The auto-injector pen is pre-filled and the needle is very small. Most people find the process much easier than they expected after the first time.

Is Zepbound the same drug as Mounjaro?

Yes — exact same drug (tirzepatide). Mounjaro is approved for type 2 diabetes; Zepbound is approved for weight loss. Same doses.

Small to moderate amounts are generally permitted, but alcohol adds calories and can worsen nausea — especially in the first few months during dose increases. No blanket ban, but many people find they naturally drink less on GLP-1 drugs.

What happens when I stop?

In the SURMOUNT-4 trial, people who stopped tirzepatide regained about half of the weight they had lost within a year — going from 20.9% below their starting weight to roughly 10% below. Obesity is a chronic condition — most people need long-term treatment to maintain results.

What if I can't afford it?

Eli Lilly's LillyDirect programme offers Zepbound at a reduced price for eligible patients without insurance — about $299/month. Ask your doctor or pharmacist. List price is ~$1,086/month.

Zepbound & Mounjaro (Tirzepatide)

Key facts

At a glance

The numbers you need before deciding.

Weight loss

20.9%

~46 lbs for a 220 lb person

Monthly cost

$299–$449/mo

Eli Lilly's LillyDirect savings programme may reduce cost to ~$299/month for eligible patients without insurance. List price is ~$1,086/month.

How you take it

Weekly injection

Pre-filled pen, no preparation needed

Main side effect

Nausea

About 3 in 10 people · usually temporary

Fat vs lean

75% fat

25% lean · SURMOUNT-1 body scan sub-study

If you stop

~11% regain

Within 1 year · SURMOUNT-4 (2024)

Before you start

Learn about this treatment

Everything you'd want to know before deciding.

Weight loss resultsTrial data, timelines, what's realistic Side effectsRates, what helps, and when to call your doctor Cost & savingsList price, insurance, manufacturer programs How it works & dosageDual GIP/GLP-1 medicine — activates two hunger signals — dose levels and what that means for you

Show 3 more

Clinical evidence5 trials, all linked Zepbound vs MounjaroSame drug, different labels — what the difference is See every treatment on one pageWhere this drug sits alongside older medicines, devices, procedures and surgery

On treatment

Already taking this?

Practical guides for people currently on this medication.

Dose titration schedule2.5mg → 5 → 7.5 → 10 → 12.5 → 15mg Not losing weight yet?Troubleshooting — what to check first Nausea or GI issuesWhat helps right now — from trial data Missed a doseWhen to take it, when to skip

Show 3 more

Injection guideSites, rotation, step-by-step What to eatProtein targets, meal timing, appetite shifts Week-by-week journeyWhat to expect from week 1 to month 12

Compare

Side-by-side comparisons

See how this drug compares with another, side by side.

Zepbound vs WegovyFull side-by-side comparison Tirzepatide vs OrforglipronFull side-by-side comparison Injection vs Pill: Tirzepatide vs Oral SemaglutideFull side-by-side comparison Zepbound vs SaxendaFull side-by-side comparison

Show 3 more

Zepbound vs QsymiaFull side-by-side comparison Zepbound vs ContraveFull side-by-side comparison Zepbound vs XenicalFull side-by-side comparison

Clinical evidence

How it compares in trials

Average weight loss % — from individual phase 3 trials

Zepbound / Mounjaro20.9%

Oral Wegovy (semaglutide pill)16.6%

Wegovy (semaglutide injection)14.9%

Qsymia (phentermine/topiramate)9.8%

Body composition and what happens after stopping

What does the lost weight consist of?

75% fat25% muscle

Fat mass — the primary target of treatmentMuscle, bone, water

Resistance training (weight lifting, bodyweight exercises) can significantly reduce the muscle loss. Aim for 2–3 sessions per week during weight loss.

Source: SURMOUNT-1 body scan sub-study

What happens when you stop

Source: SURMOUNT-4 (2024)

−20.9%

Lost on
medication

+11%

Regained
after stopping

−9.9%

Still below start
after 1 year

In studies, people regained about 53% of the weight they lost within a year of stopping — ending about 9.9% below their starting weight. This is the body returning to its defended weight — not a personal failure. Current evidence supports long-term use for people who respond well.

Is this right for you?

Who this tends to fit

Relevant if you

Open to a weekly injection
Want a weekly injection with large trial data (SURMOUNT-1: up to 20.9%)
Comfortable with a higher monthly cost ($299–$449/month)
BMI 30+ or 27+ with health conditions

Not right if you

You have a personal or family history of medullary thyroid cancer
You have a history of pancreatitis
You are pregnant or planning to become pregnant
Your BMI is below 27 without qualifying health conditions

Prefer a pill? Wegovy (semaglutide) is available as a daily pill for $149–$299/month and shows similar weight loss in trials.

Safety

Important cautions

In animal studies, tirzepatide caused thyroid tumours. It is unknown whether this applies to humans, but it is not prescribed to people with a personal or family history of medullary thyroid cancer.
Stop taking and contact your doctor immediately if you have persistent severe abdominal pain — this may be a sign of pancreatitis.
This drug may increase the risk of gallbladder problems. Tell your doctor if you develop sudden upper abdominal pain.

Read the boxed warning explained in full. See what the label says about pregnancy and breastfeeding. Availability varies by pharmacy — check current shortage status.

Practical guide

How to take Zepbound & Mounjaro

Inject under the skin of your thigh, abdomen, or upper arm — once per week, on the same day each week

Starting dose is 2.5mg. Your doctor will increase it every 4 weeks — up to a maximum of 15mg

Store in the refrigerator (36–46°F). Can be kept at room temperature for up to 21 days if needed

Each pen is pre-filled and single-use — no dose preparation needed

Common questions

FAQ

For the full regain timeline, week by week, see what the trials found after stopping.

Questions to ask your doctor

→Am I a good candidate given my health history and any other conditions I have?
→Do I have any contraindications I should know about?
→What results should I realistically expect, and over what timeframe?
→Which side effects should make me contact you?
→How long should I try this before we decide if it's working?
→What happens if I need to stop — how do I come off it safely?

Written and maintained by one person · Built with agentic AI tools · Every number checked against the cited trial · Not medical advice

How this site is built →

Next step most people take

Compare all optionsSee how this stacks up against other treatments Am I eligible?Check if this type of medication is right for you Talk to your doctorWhat to bring up at your next appointment Side effects comparedHow side effects differ across all treatments

Was this page helpful?

Medical disclaimer: This website is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any treatment. Prices shown are United States self-pay or list prices and vary by insurance and country.

At a glance

Learn about this treatment

Already taking this?

Side-by-side comparisons

How it compares in trials

Who this tends to fit

Important cautions

How to take Zepbound & Mounjaro

FAQ

Sources & references

Next step most people take