Tirzepatide
Tirzepatide is a once-a-week injection for weight loss and type 2 diabetes. It is FDA-approved as Mounjaro and Zepbound. It acts like two natural gut hormones, GLP-1 and GIP, that help control hunger and blood sugar. Semaglutide acts like one of them, and retatrutide adds a third.
What it’s studied for
- Weight lossStudied in humans
In a 72-week trial, people on the top dose lost about a fifth of their body weight. source
- Compared with semaglutideStudied in humans
In a head-to-head trial, people lost about 20% on tirzepatide and about 14% on semaglutide. source
- Blood sugarStudied in humans
In people with type 2 diabetes, HbA1c, a long-term blood sugar marker, fell by up to 2.3 points. source
2 more uses studied
- Sleep apneaStudied in humans
In people with obesity and sleep apnea, breathing pauses during sleep fell by up to 63%. About half no longer had sleep apnea. source
- Liver inflammationStudied in humans
Fatty liver inflammation cleared in up to about 6 in 10 people, against 1 in 10 on placeboplaceboAn inactive version given to some trial participants so the real effect can be measured fairly.. source
New here? Three things worth knowing first
What’s a peptidepeptideA short chain of amino acids. Proteins are long chains; peptides are short ones, usually under 50 amino acids.? A short chain of amino acids, the building blocks of protein. Many act like messengers in the body.
Why the vial has to be mixed. It ships as a dry powder. You add bacteriostatic waterbacteriostatic waterSterile water with a little benzyl alcohol that stops bacteria growing, so a mixed vial lasts days or weeks. Often called BAC water., and the amount you add decides how many unitsunitsMarks on an insulin syringe. On a U-100 syringe, 100 units = 1 mL. How many units equal a dose depends on how much water was added. on the syringe equal one dose. The calculator does that math.
SubcutaneoussubcutaneousUnder the skin, into the fat layer. The usual route for peptide injections. Often shortened to sub-Q. injection, Once weekly, same day. Subcutaneous means into the fat layer just under the skin. It uses a small insulin syringe. Any word with a dotted underline on this page opens a short definition.
Dosage guidelines
Once a week, on the same day. The dose starts at 2.5 mg and goes up every 4 weeks, to a top dose of 15 mg.
The doses below come from published reference protocols and, where they exist, the human trials. Tap a row to load it into the calculator.
Figures reviewed against their sources in October 2026. Where a trial or approved label sets a schedule, it is shown first; where a label sets one fixed dose, the FAQ below says so.
Standard titration. Starts at 2.5 mg and goes up by 2.5 mg every 4 weeks, reaching 15 mg from week 21. The 2.5 mg start is never skipped.
The FDA label and trial schedule · 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, once weekly, same day · Ongoing; up 2.5 mg every 4 weeks, with 15 mg the maximum from week 21
| Step | Weeks | Weekly dose | Draw to |
|---|---|---|---|
| 1 | Weeks 1–4 | 2.5 mg (2,500 mcg) between 5-unit marks | 12.5 units |
| 2 | Weeks 5–8 | 5 mg (5,000 mcg) | 25 units |
| 3 | Weeks 9–12 | 8 mg (8,000 mcg) rounded to the nearest 5-unit mark; the source says 7.5 mg | 40 units |
| 4 | Weeks 13–16 | 10 mg (10,000 mcg) | 50 units |
| 5 | Weeks 17–20 | 13 mg (13,000 mcg) rounded to the nearest 5-unit mark; the source says 12.5 mg | 65 units |
| 6 | Weeks 21+ | 15 mg (15,000 mcg) | 75 units |
Doses marked “between 5-unit marks” sit between the 5-unit lines on a 1 mL syringe; the 1-unit lines on a 0.5 mL or 0.3 mL syringe make them easier to read.
Units are for a 20 mg vial mixed with 1 mL of water. Change the vial in the calculator
Full protocol details
Other protocols described
- Studied maintenance doses. Trials tested 5, 10 and 15 mg. Each step up added less, and 10 mg alone gave about 20% weight loss.
Standard titration
The FDA label and trial schedule
- Dose
- 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg
- How often
- Once weekly, same day
- Timing
- Any time of day; no fasting needed
- Route
- Subcutaneous: abdomen, thigh or upper arm, rotating sites
- How long
- Ongoing; up 2.5 mg every 4 weeks, with 15 mg the maximum from week 21
- Break
- No off-period stated
The 2.5 mg start is never skipped. Dose increases are framed as countering tolerance, not chasing bigger results.
Studied maintenance doses
The doses tested in SURMOUNT and SURPASS
- Dose
- 5, 10 or 15 mg
- How often
- Once weekly
- Route
- Subcutaneous
- How long
- Ongoing
Returns shrink at the top: going from 5 to 10 mg added about 4.5 points of weight loss, and 10 to 15 mg about 1.5. Many people are described as not needing 15 mg, with 10 mg giving about 20%. Losing 1 to 2 lb a week with tolerable side effects is described as a reason to stay on the current dose; with rough side effects, protocols hold the dose longer, drop back a step or use a smaller increase.
Cycle
Ongoing; up 2.5 mg every 4 weeks, with 15 mg the maximum from week 21; No off-period stated
When a step up happens
User reports describe stepping up only after progress has stalled for two weeks or more, and only if the previous step was tolerated. Everyone is different.
Timing: Any time of day; no fasting needed.
Peptide calculator
Already filled with this vial. Change anything you like.
How much is in your vial?
Check the label. The most common strengths:
Every 10 units = 1 mg.
25 units. 2 mL of BAC water
How the vial is mixed
The powder has to be dissolved in bacteriostatic (BAC) water before use. For a 20 mg vial this page uses 1 mL, which puts the usual dose on a round syringe mark: every 10 units is 2 mg.
STEP 1Wipe both topsAlcohol pad on the peptide vial and the BAC water vial.
STEP 2Draw 1 mL of waterOne full 1 mL syringe.
STEP 3Add it slowlyAim at the glass wall, not at the powder.
STEP 4Swirl, don’t shakeRoll gently until clear. Refrigerate after.What to watch for
- Nausea, diarrhea, constipation or vomiting, mostly in the weeks after a dose increaseStudied in humans
- Gallbladder problems, which were uncommon in trialsStudied in humans
- An inflamed pancreas (pancreatitis), which was rare in trialsStudied in humans
- Hair thinning during fast weight lossReported by users
- Sulfur burps and tiredness early onReported by users
Not for anyone with a personal or family history of medullary thyroid cancer or MEN 2 (a rare inherited gland condition). Also not for pregnancy, breastfeeding or a past serious allergy to tirzepatide. Talk to a doctor first, especially alongside insulin, sulfonylurea diabetes pills or birth-control pills.
Reasons to get medical help right away: vomiting that won’t stop, severe stomach pain, signs of an allergic reaction, changes in vision, or signs of dehydration.
Full side-effect list and who should avoid it
In published research
- Nausea: 25 to 30%, dose-dependent
- Diarrhea: up to 23%
- Also vomiting, constipation, low appetite and stomach discomfort; mostly mild to moderate and during dose increases
- Stopped for side effects: 4.3% to 7.1% vs 2.6% on placebo (SURMOUNT-1)
- Acute pancreatitis: 0.23 vs 0.11 per 100 patient-years against comparators in diabetes trials; 0.14 vs 0.15 against placebo in obesity trials
- Acute gallbladder disease: about 0.6% vs 0% on placebo in weight-loss trials
- Thyroid C-cell tumors in animal studies, dose-dependent; no medullary thyroid cancer in any human trial
- In FDA adverse-event reports from 2022 to 2025, stomach and gut problems were the most reported category
What users report
- Common: nausea, constipation, diarrhea, low appetite, early tiredness, sulfur burps, bloating, reflux
- Less common: hair thinning, injection-site reactions, headache, dizziness, insomnia tied to undereating, aches and joint pain
- Rare: gallbladder problems, severe stomach pain, allergic reactions
Not for
- Personal or family history of medullary thyroid cancer, or MEN 2 (a label contraindication)
- Past serious allergy to tirzepatide
- Pregnancy or breastfeeding (no safety data)
Use caution with
- History of pancreatitis
- Gallbladder disease
- Type 1 diabetes (not approved for it)
- Diabetic eye disease (retinopathy)
- Gastroparesis or other gut motility disorders
- Kidney disease, because of dehydration
- Insulin or sulfonylureas, which may need large dose cuts
- Oral drugs where timing matters, since absorption may slow
- Oral contraceptives (see the questions above)
- Monitoring described: fasting glucose and HbA1c, lipids, liver and kidney function, testosterone in men, body composition
- Reasons to contact a doctor: persistent vomiting, severe stomach pain, signs of allergy, vision changes, dehydration
How the body handles it
- 39 amino acids, built on the GIP sequence
- Fatty side chain binds albumin
- Half-life about 5 days, so dosed weekly
- Binds the GIP receptor about as strongly as natural GIP
Supplies
What 12 weeks of the schedule above takes, counted dose by dose.
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Stacking
The community uses tirzepatide alongside recovery and growth-hormone peptides, with no interactions described. None of these pairings has been tested in a trial.
Also used alongside it, with no interactions described: BPC-157 and TB-500, growth-hormone peptides, MOTS-c and 5-Amino-1MQ, and testosterone therapy.
Not combined with: Semaglutide, retatrutide or other GLP-1 drugs, because they act on the same targets.
Go deeper
Every study, community report and source behind this page.
What the studies show20 findings, each with its evidence label
Status, October 2026. FDA-approved as Mounjaro (May 2022, type 2 diabetes) and Zepbound (Nov 2023, chronic weight management; Dec 2024, moderate-to-severe obstructive sleep apnea in adults with obesity). The FDA declared its shortage over in late 2024, which ended broad compounding. Source
How it works
The GLP-1glp-1A gut hormone that affects appetite and blood sugar. Several weight-management compounds act on its receptor. side works the way semaglutide does. On its label and in human trials, it releases insulin only when blood sugar is high, slows stomach emptying, lowers the liver's sugar output and reduces appetite and the reward value of food.
The GIP side binds the GIP receptor about as strongly as the body's own GIP. It is credited with a better insulin response after meals, steadier blood sugar and better handling of nutrients, and it may also affect fat-tissue metabolism and how well the drug is tolerated.
In lab studies, tirzepatide is a "biased" agonist at the GLP-1 receptor: it favors one signaling route (cAMP) over another (beta-arrestin), so fewer receptors are pulled inside the cell. That is proposed as one reason it keeps working with fewer stomach and gut side effects.
Together, the two actions add up to stronger appetite suppression. Downstream, human trials found less visceral fatvisceral fatFat stored deep around the organs, as opposed to the fat under the skin., lower insulin resistance and better blood pressure, blood lipids and liver fat.
Benefits
Each one carries an evidence label, so you can see how much is actually known.
Weight loss
In SURMOUNT-1, adults lost 15.0%, 19.5% and 20.9% of body weight on 5, 10 and 15 mg over 72 weeks, against 3.1% on placeboplaceboAn inactive version given to some trial participants so the real effect can be measured fairly.. source
More loss than semaglutide
In the head-to-head SURMOUNT-5 trial, tirzepatide lost 20.2% and semaglutide 13.7% at 72 weeks. source
Body composition
In a body-scan analysis of SURMOUNT-1, about 75% of the weight lost was fat and 25% lean tissue. A review of six trials found fat mass fell while lean mass was relatively preserved. source
Blood sugar
In people with type 2 diabetes, HbA1c fell by up to 2.3 percentage points (SURPASS-2). source
Blood pressure and lipids
In SURMOUNT-1, blood pressure, LDL cholesterol and triglycerides fell and HDL cholesterol rose. source
Liver fat and MASH
In a phase 2phase 2A mid-stage human trial that tests dose and early effect in hundreds of people. Phase 3 confirms results in thousands. trial in adults with fatty liver inflammation and scarring, MASH resolved in 44 to 62% on tirzepatide against 10% on placebo. source
Sleep apnea
In SURMOUNT-OSA, breathing interruptions during sleep fell by up to 62.8%, and the condition resolved in about half of participants. source
Testosterone in men
Conference data presented in 2025 reported higher testosterone in men with obesity on tirzepatide. No peer-reviewed paper is cited for it yet.
Once-weekly dosing
On its label, a half-lifehalf-lifeHow long it takes for half of a compound to leave the body. A longer half-life usually means less frequent dosing. of about 5 days allows one injection a week. source
What the science shows
SURMOUNT-1 (human, 72 weeks)
Studied in humans2,539 adults with obesity and no diabetes. Weight fell 15.0%, 19.5% and 20.9% on 5, 10 and 15 mg vs 3.1% on placeboplaceboAn inactive version given to some trial participants so the real effect can be measured fairly.; 22.5% on 15 mg among people who stayed on treatment. On 15 mg, 91% lost at least 5%, over half at least 20% and 36% at least 25%. Stopping for side effects: 4.3% to 7.1% vs 2.6% on placebo. The trial ran 72 weeks in a mostly white, female population. source
SURMOUNT-4, staying on vs stopping (human, 88 weeks)
Studied in humans670 adults lost 20.9% over a 36-week lead-in, then were randomized to continue or switch to placebo for 52 weeks. Continuing reached 25.3% at 88 weeks; placebo regained 14.0%. 89.5% vs 16.6% kept at least 80% of their loss. Only people who responded in the lead-in were randomized. source
SURMOUNT-5, head to head with semaglutide (human, 72 weeks)
Studied in humans751 adults without diabetes on tirzepatide 10 or 15 mg vs semaglutide 1.7 or 2.4 mg. Weight fell 20.2% vs 13.7% and waist size 18.4 cm vs 13.0 cm. Stopping for stomach and gut side effects: 2.7% vs 5.6%. source
SURPASS-2, type 2 diabetes (human, 40 weeks)
Studied in humans1,879 people with type 2 diabetes on tirzepatide 5, 10 or 15 mg vs semaglutide 1 mg. Every tirzepatide dose was at least as good and better at lowering HbA1c, with more weight loss. Semaglutide was tested at 1 mg, below its weight-loss dose. source
SURPASS-CVOT, heart events (human, 4 years)
Studied in humans13,165 people with type 2 diabetes and heart or artery disease, compared with dulaglutide over a median 4 years. Heart-related death, heart attack or stroke: 12.2% vs 13.1%. That met the bar for being no worse (P = 0.003) but not for being better (P = 0.09). source
SURMOUNT-OSA, sleep apnea (human, 52 weeks)
Studied in humansTwo randomized trials. Breathing interruptions per hour fell by up to 62.8%, sleep apnea resolved in about half, and blood pressure and an inflammation marker (hsCRP) improved. source
SYNERGY-NASH, fatty liver (human, phase 2, 52 weeks)
Studied in humans190 adults with biopsy-confirmed MASH and liver scarring. MASH resolved in 44%, 56% and 62% on 5, 10 and 15 mg vs 10% on placebo, and about half improved by at least one scarring stage. source
Body composition in SURMOUNT-1 (human, DXA)
Studied in humansPost hoc scans in 160 participants (124 on tirzepatide, 36 on placebo). Body weight fell 21.3%, fat mass 33.9% and lean mass 10.9%: about 75% fat and 25% lean, a ratio similar to placebo's. source
Muscle across trials (human, systematic review)
Studied in humansSix randomized trials. Fat mass fell while lean mass was relatively preserved. source
How it signals (lab)
Studied in animals or labLab work described tirzepatide as an "imbalanced and biased" dual agonist: weighted toward GIP, and favoring cAMP signaling at the GLP-1glp-1A gut hormone that affects appetite and blood sugar. Several weight-management compounds act on its receptor. receptor. source
Birth-control pills (human)
Studied in humansPeak levels of ethinyl estradiol, the estrogen in many pills, fell 59% and overall exposure 20%. source
What the community reports7 user reports, a timeline and 6 pairings
What to expect
Mild to moderate appetite suppression and common nausea. Users describe 0 to 10 lb lost, much of it water.
Reported by usersA steady 1 to 3 lb a week, less "food noise", and side effects settling.
Reported by usersDescribed as the window of peak effect.
Reported by usersLoss slows toward a plateau. In SURMOUNT-1 most of the loss came in the first 40 weeks, and some people on higher doses were still losing at week 72.
Studied in humansIn SURMOUNT-4, people who stayed on treatment reached 25.3% total loss, and 89.5% kept at least 80% of what they had lost.
Studied in humansIn SURMOUNT-4, people switched to placeboplaceboAn inactive version given to some trial participants so the real effect can be measured fairly. regained 14.0% of body weight over the next year.
Studied in humansThe titrationtitrationStepping a dose up (or down) gradually over time, every few weeks (every four weeks in the GLP-1 drug trials), instead of starting at the full amount. phase lasts 4 to 20 weeks depending on the target dose. The lifestyle base described alongside it is protein of 1 g per pound of goal body weight a day (someone at 250 lb aiming for 190 lb would eat 190 g), resistance training at least 2 to 3 times a week, 7 to 9 hours of sleep and daily walking.
What people report
Gathered from user communities. Anecdotal: useful for what to expect, not proof.
Weight lost
Users describe 15 to 25 lb in the first 3 months and 40 to 60 lb over 6 to 12 months, with better results when protein and lifting are in place.
Stomach and gut
Nausea in the first one to two weeks of each dose, very common constipation, some diarrhea, "sulfur burps" and tiredness early on.
Hair thinning
Reported during rapid loss and attributed to temporary shedding (telogen effluvium) from the calorie deficit.
Muscle
Users who skip protein and lifting describe looking "skinny fat". Those eating 1 g of protein per pound of goal weight and lifting 2 to 3 times a week describe keeping or gaining muscle.
Plateaus
Often after about 6 months, usually traced to low protein, too little training or a dose that has stopped working. Habits are described as the first thing revisited, before the dose.
Sleep
Insomnia is described and tied to undereating: an overnight blood-sugar dip and cortisol rise, with waking around 2 AM. Users describe eating more during the day and a protein snack at bedtime.
Compared with retatrutide
Users describe retatrutide as stronger for stubborn fat, and tirzepatide as effective with the advantage of FDA approval.
Stacking
How it is described alongside other compounds.
BPC-157 and TB-500
No interaction described; the mechanisms are different and there is no timing conflict.
Growth-hormone peptides (CJC-1295, ipamorelin, sermorelin)
No interaction described. The growth-hormone peptides keep their fasting schedule, with tirzepatide injected separately.
MOTS-c and 5-Amino-1MQ
No interaction described.
Testosterone therapy
No interaction described. Weight loss is described as possibly restoring natural testosterone where low levels are linked to obesity, and monitoring labs is described.
Semaglutide, retatrutide or other GLP-1 drugs
Not combined. They share the GLP-1 target, and retatrutide shares GIP as well.
Switching to retatrutide
Protocols describe giving retatrutide at 2 mg on the next scheduled tirzepatide day, whatever the tirzepatide dose was, because the glucagon receptor is new to the body and needs its own titration. Some return of appetite over the following weeks is described.
Common questions10 questions
Common questions
Is the step-up schedule necessary?
Protocols describe it as required, starting at 2.5 mg. Starting high is described as causing heavy stomach and gut side effects.
Does the weight come back after stopping?
In SURMOUNT-4, people switched to placebo regained 14.0% of body weight within a year, and only 16.6% kept at least 80% of their loss, against 89.5% of those who stayed on. Habits built while on it are described as what decides the rest.
Is it better than semaglutide?
The trial data favors it: 20.2% vs 13.7% in SURMOUNT-5, with fewer people stopping for side effects. Semaglutide still works, and muscle retention takes more attention on it.
Is muscle lost?
In the SURMOUNT-1 scans, about 25% of the weight lost was lean tissue. Low protein and no resistance training are described as the main drivers of muscle loss.
How does it compare with retatrutide?
Retatrutide adds a third receptor (glucagon). In TRIUMPH-1 it gave 25.0% average loss on 12 mg at 80 weeks vs 3.9% on placebo. It is investigational and not approved, while tirzepatide is FDA approved.
Does it affect birth-control pills?
Yes. In a study, peak estrogen levels from the pill fell 59% and overall exposure 20%. The label notes the pill may work less well for 4 weeks after starting and after each dose increase, which is why a non-oral method or a backup method is described for those windows.
Why can sleep get worse?
Usually undereating, by users' accounts: blood sugar dips overnight and cortisol rises. Eating more during the day and a protein snack at bedtime are what users describe.
Can it be stacked with retatrutide?
No. They share the GLP-1 and GIP targets.
What does “minimum effective dose” mean?
It is the lowest dose that still produces the effect someone is after. User reports describe starting there and staying there for as long as it keeps working, rather than climbing toward the top of the range. Side effects tend to rise with dose, and the top of each range on this page is a ceiling people report, not a target.
When does the dose go up?
In the trials, the dose went up on a fixed schedule, because a trial has to treat everyone the same way. User reports describe a different pattern outside trials: staying on a dose while it is still working, and moving up only after progress has stalled for two weeks or more and side effects have settled. There is no prize for getting to the top dose fast. These are not quick fixes: most of what people report builds over weeks, not days.
Source material12 studies and documents
References
- Jastreboff AM, et al. N Engl J Med. 2022;387(3):205-216. pubmed.ncbi.nlm.nih.gov/35658024/…
- Aronne LJ, et al. JAMA. 2024;331(1):38-48. pubmed.ncbi.nlm.nih.gov/38078870/…
- Aronne LJ, et al. N Engl J Med. 2025;393(1):26-36. pubmed.ncbi.nlm.nih.gov/40353578/…
- Frias JP, et al. N Engl J Med. 2021;385(6):503-515. pubmed.ncbi.nlm.nih.gov/34170647/…
- SURPASS-CVOT. N Engl J Med. 2025;393(24):2409-2420. pubmed.ncbi.nlm.nih.gov/41406444/…
- Malhotra A, et al. N Engl J Med. 2024;391(13):1193-1205. pubmed.ncbi.nlm.nih.gov/38912654/…
- Loomba R, et al. N Engl J Med. 2024;391(4):299-310. pubmed.ncbi.nlm.nih.gov/38856224/…
- Look M, et al. Diabetes Obes Metab. 2025;27(5):2720-2729. pubmed.ncbi.nlm.nih.gov/39996356/…
- Hidalgo Ramos RA, et al. Cureus. 2025. pubmed.ncbi.nlm.nih.gov/40895971/…
- Willard FS, et al. JCI Insight. 2020;5(17):e140532. pubmed.ncbi.nlm.nih.gov/32730231/…
- Skelley JW, et al. J Am Pharm Assoc. 2024;64(1):142-148. pubmed.ncbi.nlm.nih.gov/37940101/…
- Jastreboff AM, et al. N Engl J Med. 2026. www.nejm.org/doi/full/10.1056/NEJMoa2604169…
Related
What is Tirzepatide?
Tirzepatide is a synthetic peptidepeptideA short chain of amino acids. Proteins are long chains; peptides are short ones, usually under 50 amino acids. of 39 amino acids, built on the sequence of the gut hormone GIP and designed to activate both the GIP and GLP-1glp-1A gut hormone that affects appetite and blood sugar. Several weight-management compounds act on its receptor. receptors. A fatty side chain binds it to albumin in the blood, giving a half-lifehalf-lifeHow long it takes for half of a compound to leave the body. A longer half-life usually means less frequent dosing. of about 5 days and once-weekly dosing. Eli Lilly makes it. The FDA approved it as Mounjaro in May 2022 for type 2 diabetes, and as Zepbound in November 2023 for chronic weight management (obesity, or overweight with at least one weight-related condition). In December 2024 Zepbound was also approved for moderate-to-severe obstructive sleep apnea in adults with obesity. It is being studied in fatty liver disease (MASH), a form of heart failure (HFpEF) and other metabolic conditions. Researchers once expected that blocking GIP would help weight loss. Activating it alongside GLP-1 turned out to work better. In the peptide market it is often listed as GLP2 or GLP2-TZ. That is a product name only. GLP-2 is a different gut hormone with a different job, and tirzepatide does not act on it.
What people look into Tirzepatide for
Every line carries an evidence label, so you can see how much is actually known.
Weight loss: In SURMOUNT-1, adults lost 15.0%, 19.5% and 20.9% of body weight on 5, 10 and 15 mg over 72 weeks, against 3.1% on placeboplaceboAn inactive version given to some trial participants so the real effect can be measured fairly..source
Studied in humansMore loss than semaglutide: In the head-to-head SURMOUNT-5 trial, tirzepatide lost 20.2% and semaglutide 13.7% at 72 weeks.source
Studied in humansBody composition: In a body-scan analysis of SURMOUNT-1, about 75% of the weight lost was fat and 25% lean tissue. A review of six trials found fat mass fell while lean mass was relatively preserved.source
Studied in humansBlood sugar: In people with type 2 diabetes, HbA1c fell by up to 2.3 percentage points (SURPASS-2).source
Studied in humansBlood pressure and lipids: In SURMOUNT-1, blood pressure, LDL cholesterol and triglycerides fell and HDL cholesterol rose.source
Studied in humansLiver fat and MASH: In a phase 2phase 2A mid-stage human trial that tests dose and early effect in hundreds of people. Phase 3 confirms results in thousands. trial in adults with fatty liver inflammation and scarring, MASH resolved in 44 to 62% on tirzepatide against 10% on placebo.source
Studied in humansSleep apnea: In SURMOUNT-OSA, breathing interruptions during sleep fell by up to 62.8%, and the condition resolved in about half of participants.source
Studied in humansTestosterone in men: Conference data presented in 2025 reported higher testosterone in men with obesity on tirzepatide. No peer-reviewed paper is cited for it yet.
UnknownOnce-weekly dosing: On its label, a half-lifehalf-lifeHow long it takes for half of a compound to leave the body. A longer half-life usually means less frequent dosing. of about 5 days allows one injection a week.source
Studied in humansMix and measure: a 20 mg vial
Go deeper
How it works, in plain words
The GLP-1glp-1A gut hormone that affects appetite and blood sugar. Several weight-management compounds act on its receptor. side works the way semaglutide does. On its label and in human trials, it releases insulin only when blood sugar is high, slows stomach emptying, lowers the liver's sugar output and reduces appetite and the reward value of food.
What did the study measure?
No single study is featured for Tirzepatide; the human trials are linked from the uses above.
Sources
Side effects and who should avoid it
Side effects and limits, stated plainly. If anything here applies to you, talk to a doctor first.