Mounjaro and Thyroid Medication: Is It Safe? Label, Studies
No thyroid pill interaction is listed, but Mounjaro can change how pills absorb; get levels checked.
- Verdict
- Fine with care
- Label names it
- No
- General caution
- Pills absorbed more slowly
Check a GLP-1 interaction
Mounjaro key facts
Its half-life is about 5 days. After 5 d, half is gone, and about 3% remains after five half-lives (25 d).
In SURPASS-1, people with type 2 diabetes lost 7.8 kg over 40 weeks, compared with 1 kg on placebo.
The maker's price page provides monthly prices in US dollars for the list price and self-pay offers.
Sources: FDA label (DailyMed), healthsystemtracker.org, pricinginfo.lilly.com.
Mounjaro and thyroid medication: the verdict
Fine with care
The Mounjaro label provides this exact drug interactions text:
“MOUNJARO delays gastric emptying and thereby has the potential to impact the absorption of concomitantly administered oral medications. Caution should be exercised when oral medications”
Source: FDA label (DailyMed)
What the Mounjaro label says
The Mounjaro label does not name thyroid medicine (levothyroxine). These lines still apply to it.
| Named in the label | The risk | What the label tells doctors |
|---|---|---|
| Oral medicines | Pills absorbed differently | It slows how quickly the stomach empties, and that can affect how other pills are absorbed. |
Source: Mounjaro label (DailyMed).
What the studies show
- Content in the Drug Interactions section of the label
- interaction in the label involving oral medicines
- the way levothyroxine is taken on an empty stomach
- worsening blood sugar control that may occur with levothyroxine and diabetes medicines
Source: FDA label (DailyMed)
The practical rule
- Keep taking levothyroxine as directed. After starting, ask your doctor whether your thyroid levels need another check.
- Tell your GLP-1 prescriber about every pill you take, including this one.
- Check with your pharmacist about whether any of your pills need a steady blood level. You may need those levels checked when you begin the dose or increase it.
Source: FDA label (DailyMed)
Thyroid medication with other GLP-1s
We reviewed the drug interaction section in each label to see whether the same issue appears.
| Medicine | Thyroid medicine (levothyroxine) in the label | Verdict | Page |
|---|---|---|---|
 Ozempic | Not named; general pill caution | Not listed | Not listed |
 Wegovy | Named in the label | Not listed | Not listed |
 Rybelsus | Named in the label | Fine with care | Read the answer |
| Mounjaro | Not named; general pill caution | Fine with care | Not listed |
 Zepbound | Not named; general pill caution | Not listed | Not listed |
 Foundayo | Not named; general pill caution | Not listed | Not listed |
 Trulicity | Not named; general pill caution | Not listed | Not listed |
 Saxenda | Not named; general pill caution | Not listed | Not listed |
 Victoza | Not named; general pill caution | Not listed | Not listed |
| Byetta | Not named; general pill caution | Not listed | Not listed |
Source: FDA label (DailyMed)