tirzepatide (Mounjaro)

Adjunctive therapy

Brands: MOUNJARO

Last reviewed 2026-02-12

Reviewed by PsychMed Editorial Team.

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Quick answers

What is tirzepatide (Mounjaro)?
Mounjaro is a once-weekly injectable form of tirzepatide, a dual GIP/GLP-1 receptor agonist indicated for type 2 diabetes (label).
What is MOUNJARO?
MOUNJARO is a brand name for tirzepatide (Mounjaro).
What is MOUNJARO (tirzepatide (Mounjaro)) used for?
Label indications include: Type 2 diabetes mellitus (adjunct to diet/exercise) (label). No FDA-approved psychiatric indications.
What drug class is MOUNJARO (tirzepatide (Mounjaro))?
Weekly injectable dual GIP/GLP-1 receptor agonist (tirzepatide) indicated for type 2 diabetes. It produces substantial weight loss in many patients, which can be relevant when metabolic comorbidity complicates psychiatric care, but it has no FDA-approved psychiatric indications.
What strengths does MOUNJARO (tirzepatide (Mounjaro)) come in?
Single-dose pens for subcutaneous injection once weekly (label).

Snapshot

Primary label indications include: Type 2 diabetes mellitus (adjunct to diet/exercise) (label).
Class: Adjunctive therapy
Common US brands: MOUNJARO
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2026-02-12

Label indications

Type 2 diabetes mellitus (adjunct to diet/exercise) (label). No FDA-approved psychiatric indications.

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Clinical Highlights

Mounjaro is a once-weekly injectable form of tirzepatide, a dual GIP/GLP-1 receptor agonist indicated for type 2 diabetes (label). It is not a psychiatric medication and has no FDA-approved psychiatric indications. In mental health care, its relevance is usually metabolic (diabetes/obesity that complicate treatment or cardiometabolic risk from weight-gain–promoting psychotropics) (clinical).

Tirzepatide produces substantial weight loss in many patients; this can matter for serious mental illness populations where obesity and diabetes burden are high. Evidence for GLP-1–based strategies in antipsychotic- associated metabolic dysfunction is strongest at the class level and typically requires coordination with primary care/endocrinology (Review/clinical).
A key practical warning is reduced efficacy of oral hormonal contraceptives during initiation and dose escalation due to delayed gastric emptying; patients using oral contraceptives should switch to a non-oral method or add a barrier method for 4 weeks after initiation and for 4 weeks after each dose escalation (label).
The compare view, evidence feed, and print page help compare titration schedules and safety monitoring themes.

Dosing & Formulations

Mounjaro is supplied in single-dose pens for subcutaneous injection once weekly (label). Typical titration: 2.5 mg once weekly for 4 weeks (starter), then 5 mg once weekly; if additional glycemic control is needed, increase in 2.5 mg steps (7.5 mg, 10 mg, 12.5 mg, 15 mg) at 4-week intervals (label).

If a dose is missed, administer as soon as possible within 4 days (96 hours); if more than 4 days have passed, skip and resume the regular schedule. Do not take two doses within 3 days of each other (label).
Injection sites include abdomen, thigh, or upper arm; rotate sites (label).
GI tolerability often improves with slower escalation and attention to hydration and meal size (clinical).

Monitoring & Risks

Boxed warning: risk of thyroid C-cell tumors; contraindicated with personal/family history of MTC or MEN2 (label). Pancreatitis and gallbladder disease have been reported; evaluate severe or persistent abdominal pain and discontinue if pancreatitis is suspected (label).

Hypoglycemia risk increases when combined with insulin or sulfonylureas; coordinate regimen adjustments across prescribers (label/clinical).
Dehydration from vomiting/diarrhea can worsen renal function; monitor volume status and renal function when clinically indicated (label/clinical).
Females of reproductive potential using oral hormonal contraceptives need contraception counseling during initiation and dose escalation (label).

Drug Interactions

Oral hormonal contraceptives: delayed gastric emptying can reduce oral contraceptive exposure during initiation and dose escalation. Switch to non-oral contraception or add a barrier method for 4 weeks after initiation and after each dose escalation (label). When combined with other glucose-lowering medications, the main interaction risk is hypoglycemia (especially insulin or sulfonylureas) (label/clinical).

Delayed gastric emptying can also affect absorption of other oral drugs during titration; review narrow-therapeutic-index agents and time-sensitive regimens (clinical).
Major CYP-mediated interactions are not expected (peptide metabolism), but polypharmacy review is still essential (clinical).

Practice Notes

In serious mental illness care, tirzepatide is usually an “adjunctive metabolic” consideration rather than a psychiatric intervention; align expectations with realistic weight and HbA1c goals (clinical). Because GLP-1–based therapies can worsen nausea early, proactive nausea management and hydration planning can reduce missed psychotropic doses and adherence disruptions (clinical).

Coordinate diabetes medication adjustments and monitoring with primary care/endocrinology to avoid hypoglycemia or abrupt regimen changes (clinical).
Screen for disordered eating and ensure weight-loss goals are safe and appropriate; monitor for excessive appetite suppression and dehydration (clinical).
Discuss reproductive planning and oral contraceptive limitations early, particularly in populations where follow-up can be inconsistent (label/clinical).

References

MOUNJARO (tirzepatide) injection prescribing information — DailyMed (2026)
Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes — New England Journal of Medicine (2021)
Tirzepatide once weekly for the treatment of obesity — New England Journal of Medicine (2022)
Therapeutic Management OF Atypical Antipsychotic Related Metabolic Dysfunctions Using GLP 1 Receptor Agonists: A Systematic Review — Experimental and Therapeutic Medicine (2023)