Fat lossFDA-approved useSubQ

Tirzepatide

Also: Mounjaro, Zepbound

Mounjaro and Zepbound. Weekly shot that hits two appetite hormones at once. Got people up to ~22% weight loss at the high dose.

Typical dose

5 mg/wk

25u, Weekly

Cycle

Ongoing per FDA labels

Where

Abdomen, outer thigh, or upper arm

FDA titration

Weeks 1–4

12.5u

2.5 mg/wk · Weekly

FDA starting dose (non-therapeutic lead-in). Hold 4 wks; most GI side effects occur early.

Weeks 5–8

25u

5 mg/wk · Weekly

FDA step 2, first maintenance dose. Increase only after ≥4 wks.

Weeks 9–12

37.5u

7.5 mg/wk · Weekly

FDA step 3.

Weeks 13–16

50u

10 mg/wk · Weekly

FDA step 4, maintenance dose. Many stop here.

Weeks 17–20

62.5u

12.5 mg/wk · Weekly

FDA step 5. Increase only if needed.

Weeks 21+

75u

15 mg/wk · Weekly

FDA Mounjaro/Zepbound maximum. Label allows skipping 5→10 or 10→15 if tolerating well.

Phase	How often	Dose	Units	Notes
Weeks 1–4	Weekly	2.5 mg/wk	12.5u	FDA starting dose (non-therapeutic lead-in). Hold 4 wks; most GI side effects occur early.
Weeks 5–8	Weekly	5 mg/wk	25u	FDA step 2, first maintenance dose. Increase only after ≥4 wks.
Weeks 9–12	Weekly	7.5 mg/wk	37.5u	FDA step 3.
Weeks 13–16	Weekly	10 mg/wk	50u	FDA step 4, maintenance dose. Many stop here.
Weeks 17–20	Weekly	12.5 mg/wk	62.5u	FDA step 5. Increase only if needed.
Weeks 21+	Weekly	15 mg/wk	75u	FDA Mounjaro/Zepbound maximum. Label allows skipping 5→10 or 10→15 if tolerating well.

FDA, Zepbound (weight loss): 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, +4 wks per step; 2.5 mg is a starting dose, not therapeutic; escalate for maximum effect (max 15 mg). FDA, Mounjaro (type-2 diabetes): same ramp; maintenance 5, 10, or 15 mg; glycemic control; may skip 5→10 / 10→15 if tolerated.

Community

Same ramp, but many hold at 5–10 mg; microdose 2.5 for tolerance · Weekly

Titrate to effect, step up only if weight loss stalls.

Phase	How often	Dose	Units	Notes
Community	Weekly	Same ramp, but many hold at 5–10 mg; microdose 2.5 for tolerance	–	Titrate to effect, step up only if weight loss stalls.

Bottom line: the FDA ramp targets the maximum dose; community practice holds at the lowest effective dose (often 5–10 mg) to minimize nausea and cost. Both use the same 4-week step cadence.

Cycle & timing

Cycle: Ongoing per FDA labels; no scheduled off-cycle. Discontinue ≥1 month before planned pregnancy.

Where: Abdomen, outer thigh, or upper arm.

What to expect

Appetite reduction from week 1; better GI tolerance than semaglutide. ~20% average weight loss at 72 weeks. SURMOUNT-5 head-to-head (72 wks): tirzepatide 20.2% vs semaglutide 13.7%, ~47% greater relative loss.

How much to buy

For 21-wk @ 15 mg × 1/wk:

× 50mg vials

× 60mg vials

× 80mg vials

× 100mg vials

Men & women

Men: In men, excess fat lowers testosterone; GLP-1 raises total testosterone, SHBG and gonadotropins as weight drops, and improves sperm and erectile function; and preserves fertility, unlike TRT (which suppresses sperm).

Women: Women lose more than men at the same dose but report more GI (start lower). In PCOS they improve cycles, lower free testosterone and raise ovulation; a real unplanned-pregnancy risk. Stop before conceiving. Tirzepatide also cuts oral-birth-control absorption, use a backup method for ~4 weeks after each step up.

Dilution calculator

Set to the guide's typical mix for Tirzepatide. Change anything to see where to draw.

Vial size

BAC water added

Dose you want

Draw to

25u

Volume

0.25 mL

Strength

20 mg/mL

Doses per vial

Assumes a U-100 insulin syringe (100 units = 1 mL). Double-check against the compound's page before you draw.

Recommended mixes

Vial	Water	Strength
10 mg	0.50 mL	20 mg/mL
15 mg	0.75 mL	20 mg/mL
20 mg	1 mL	20 mg/mL
30 mg	1.5 mL	20 mg/mL
40 mg	2 mL	20 mg/mL
50 mg	2.5 mL	20 mg/mL
60 mg	3 mL	20 mg/mL
80 mg	4 mL	20 mg/mL
100 mg	5 mL	20 mg/mL

10 mg: 1 unit = 0.20 mg

Storage

PowderFreeze-dried: -4°F.
MixedReconstituted: 36–46°F, use within 28 days.

Don't use if: Personal or family history of medullary thyroid carcinoma (MTC) or MEN 2; personal/family history of any thyroid cancer · Personal history of pancreatitis (any cause) · Pre-existing gastroparesis or significant gastric motility disorder; severe GERD, scleroderma, or other delayed-emptying conditions · Prior serious hypersensitivity to the compound or excipients · Pregnancy and lactation; discontinue 1 month before planned conception · History of cholelithiasis / gallbladder disease · Active or pre-existing diabetic retinopathy; eating-disorder history; CKD stage 4–5

Stop if you notice

Creatinine rise >0.3 mg/dL or eGFR drop >20%: hold, rehydrate
Severe abdominal pain: evaluate for pancreatitis
Vision changes: ophthalmology
Persistent vomiting >48h: hold
New neck mass / hoarseness / dysphagia: thyroid workup

Side effects

Nausea, vomiting, diarrhea, constipation. Generally better tolerated than semaglutide.

Drug interactions

Delayed gastric emptying affects oral absorption (levothyroxine, oral contraceptives, warfarin); separate timing. Insulin / secretagogues: reduce at initiation. Do not combine with other GLP-1 agonists.

Labs

Baseline: BMP/CMP, CBC, HbA1c, lipid panel, TSH, pregnancy test. BMP at every dose escalation and any time GI side effects cause >24h reduced intake. HbA1c at 3 + 6 mo; lipids at 6 mo; repeat eGFR if dehydration. Lipase if abdominal pain. Drop hsCRP / routine calcitonin. Out of range? Rising glucose/HbA1c = blood sugar creeping toward diabetes (recheck, tighten diet); a falling eGFR = kidney strain, usually dehydration (hydrate, hold the dose).

What these labs mean →

Pregnancy & breastfeeding

Pregnancy and lactation; discontinue 1 month before planned conception.

Warnings

Acute pancreatitis: discontinue if suspected (severe abdominal pain radiating to back). Acute gallbladder disease; diabetic-retinopathy progression; acute kidney injury from GI-related volume depletion (highest during escalation). Severe GI: ileus, obstruction, severe constipation, fecal impaction. Anaphylaxis/angioedema reported. Tachycardia (1–4 bpm). Aspiration risk under anesthesia.

Patient education

Acute kidney injury on GLP-1s is from dehydration, not the drug. Target 2.5–3 L water/day; hold next dose for any day of vomiting/diarrhea/reduced food; resume same level after 24h recovery. Required during any GLP-1 cycle: protein 1.2 g/kg IBW/day (1.6 if training), resistance training 2–3×/wk, creatine 5 g/day; else 25–40% of weight lost is lean mass with rapid regain. Eat slowly, stop at first fullness. Inform any anesthesiologist before procedures (aspiration risk). Discontinue ≥1 month before planned pregnancy (shorter washout than semaglutide). Pen sharing prohibited even with a new needle.

These apply on top of the universal safety rules.

What it does

FDA indications: T2D (Mounjaro); chronic weight management (Zepbound); OSA in obesity (Zepbound, Dec 2024). MASH: Phase 3 ongoing, NOT FDA-approved.

FDA-approved dual GIP/GLP-1 agonist, gold standard for weight loss. Co-activates GIPR (appetite + insulin + fat-cell effects) and GLP-1R (satiety + gastric slowing + glucagon suppression).

FDA label vs community dosing

Approach	Ramp / dose (weekly)	Philosophy
FDA, Zepbound (weight loss)	2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, +4 wks per step	2.5 mg is a starting dose, not therapeutic; escalate for maximum effect (max 15 mg).
FDA, Mounjaro (type-2 diabetes)	Same ramp; maintenance 5, 10, or 15 mg	Glycemic control; may skip 5→10 / 10→15 if tolerated.
Community	Same ramp, but many hold at 5–10 mg; microdose 2.5 for tolerance	Titrate to effect, step up only if weight loss stalls.

Bottom line: the FDA ramp targets the maximum dose; community practice holds at the lowest effective dose (often 5–10 mg) to minimize nausea and cost. Both use the same 4-week step cadence.

Regulatory & sourcing notes

After March 19, 2025 the FDA bars compounded tirzepatide without documented clinical difference; sourcing now mostly grey-market research suppliers.
In 2026 the FDA also proposed excluding sema/tirz/liraglutide from the 503B bulks list (comments due Jun 29, 2026).
FDA indications: T2D (Mounjaro); chronic weight management (Zepbound); OSA in obesity (Zepbound, Dec 2024).
MASH: Phase 3 ongoing, NOT FDA-approved.

References

seekpeptides rxlist researchdosing peptidedosages DailyMed GLP-1 sex differences Jensterle 2020

From the guide, page 99–100.