Rybelsus and Thyroid Medication: Is It Safe? Label, Studies
Rybelsus raised levothyroxine levels by 33% in a study; your doctor may check your thyroid levels.
- Verdict
- Fine with care
- Label says
- Listed interaction
Check a GLP-1 interaction
A quick Rybelsus overview
Its half-life is about 1 week. After 7 d, half is gone; at five half-lives (35 d), about 3% remains.
In PIONEER 1, people with type 2 diabetes lost 3.7 kg over 26 weeks. The placebo group lost 1.4 kg.
The maker's price page provides monthly prices in US dollars for both the list price and self-pay offers.
Sources: FDA label (DailyMed), healthsystemtracker.org, Novo Nordisk pricing, Novo Nordisk.
Rybelsus and thyroid medication: the verdict
Fine with care
The Rybelsus label's drug interactions section states the following word for word:
“Levothyroxine exposure was increased 33% (90% CI: 1.25 to 1.42) when administered with semaglutide tablets in a drug interaction study [see Clinical Pharmacology (12.3)].”
Source: FDA label (DailyMed).
Details from the Rybelsus label
For thyroid medicine (levothyroxine), these lines in the Rybelsus label apply.
| Named in the label | The risk | What the label tells doctors |
|---|---|---|
| Oral medicines | Pills absorbed differently | It slows stomach emptying, which may alter how other pills are absorbed. |
| Levothyroxine | Thyroid hormone levels can rise | Semaglutide tablets raised levothyroxine levels in a study, so thyroid levels may need checking. |
Source: DailyMed Rybelsus label (DailyMed).
What the studies show
- 33%
- empty stomach how to take
- the way levothyroxine is taken on an empty stomach
- possible worsening of glycemic control when levothyroxine and diabetes medicines are used together
Source: FDA label (DailyMed).
The practical rule
Ask your pharmacist how far apart to take the two pills. Ask your doctor whether your thyroid levels should be checked again.
Source: FDA label (DailyMed).
Thyroid medication with other GLP-1s
The drug interaction section of each label was checked for the same issue.
| 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 | Not listed |
 Mounjaro | Not named; general pill caution | Fine with care | Read the answer |
 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).