How much weight will I lose?

Quick read · 5 min

Last reviewed: April 2026Based on 47 clinical trialsEvery claim linked to source

In clinical trials, people lost between 7% and 21% of their body weight on average — depending on the drug. For a 240 lb person, that's roughly 17 to 50 lbs.

In simple terms:
  • Average weight loss ranges from 7% (older drugs) to 21% (tirzepatide) in clinical trials.
  • For a 240 lb person, that is roughly 17–50 lbs depending on the medication.
  • About 1 in 3 people on newer drugs lose more than the average. About 1 in 5 lose less than 5%.
  • Results depend on dose reached, how long you stay on treatment, diet, and exercise.

MedicationAverage LossAt 240 lbAt 200 lb
Tirzepatide (Zepbound)
Weekly injection
20.9%~50 lbs~42 lbs
Semaglutide pill (Oral Wegovy)
Daily pill
16.6%~40 lbs~33 lbs
Semaglutide injection (Wegovy)
Weekly injection
14.9%~36 lbs~30 lbs
Orforglipron (Foundayo)
Daily pill
12.4%~30 lbs~25 lbs
Phentermine/Topiramate (Qsymia)
Daily pill
9.8%~24 lbs~20 lbs
Naltrexone/Bupropion (Contrave)
Daily pill
9.3%~22 lbs~19 lbs
Liraglutide (Saxenda)
Daily injection
8%~19 lbs~16 lbs
Orlistat (Alli/Xenical)
Pill with meals
6.9%~17 lbs~14 lbs

Tip: These are averages from clinical trials. Want to see the numbers for your weight? Try our calculator →

What this means:

These are averages. About 1 in 3 people on tirzepatide lost more than 20% of their body weight. About 1 in 5 people on any drug lose less than 5%. Your actual result depends on dose reached, adherence, diet, exercise, and individual metabolism.


Not everyone loses the same amount

These percentages are averages. In reality, people had very different outcomes. Here's what actually happened in three major clinical trials:

Semaglutide injection

(STEP 1)
Lost 20%+37%
37%
Lost 10–20%35%
35%
Lost 5–10%13%
13%
Lost <5%15%
15%

Tirzepatide 15mg

(SURMOUNT-1)
Lost 20%+57%
57%
Lost 10–20%25%
25%
Lost 5–10%8%
Lost <5%10%
10%

Orforglipron

(ATTAIN-1)
Lost 20%+25%
25%
Lost 10–20%35%
35%
Lost 5–10%20%
20%
Lost <5%20%
20%

Notice: On tirzepatide, 57% of people lost 20% or more. On the older drugs, that number drops to 25–37%. But on any drug, about 1 in 5 people lost less than 5%.


What predicts better results?

📊

Higher starting weight

More absolute pounds lost, though the percentage is similar. A heavier person losing 15% loses more total weight.

💊

Reaching maximum dose

Most weight loss happens at the highest tolerated dose. If you stay at a lower dose, you&apos;ll see less dramatic results.

🏋️

Resistance training + protein

Weight training (3–4 times per week) plus 60–100g protein daily preserves muscle and may boost fat loss.

⏱️

Staying on treatment

Weight loss continues for 12–18 months before plateauing. Stopping early means slower, smaller results.


Bottom line

  • Averages are just averages. About 1 in 3 people do better, and about 1 in 5 lose less than 5%.
  • Give any medication at least 3–6 months at the therapeutic dose before judging results.
  • Lifestyle factors (protein, resistance training) can meaningfully improve both how much you lose and how much is fat instead of muscle.

Common questions


Based on clinical trials · No rankings · Every claim linked to source

Last reviewed: April 2026

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.