GLP-1 medicines and your other pills: what the Wegovy, Zepbound, Ozempic and Foundayo labels say about absorption and interactions

The common thread: a slower stomach

GLP-1 and related medicines slow the passage of food and tablets from the stomach into the intestine. That is part of how they work, and it is also the reason every one of these labels contains a drug-interaction section about oral medicines. The concern is not that the medicines react chemically with other drugs. It is that a pill which normally dissolves and is absorbed on a predictable schedule may be absorbed a little later, or in a different pattern, while gastric emptying is slowed.

We reviewed the current prescribing information for Wegovy (injection and tablets, revised 06/2026), Ozempic, Mounjaro (revised 08/2026), Zepbound (revised 08/2026) and Foundayo (orforglipron tablets, revised 07/2026), focusing on the drug interaction sections and the clinical pharmacology data behind them. We checked them on 9 October 2026.

What each label says about oral medicines

Medicine	Section	What the label says
Wegovy (injection and tablets)	7.2 Oral Medications	Wegovy causes a delay of gastric emptying and thereby has the potential to impact the absorption of concomitantly administered oral medications. Monitor the effects of oral medications taken with Wegovy, and consider increased clinical or laboratory monitoring for medicines that have a narrow therapeutic index or that require clinical monitoring.
Ozempic	7.2 Oral Medications	Ozempic delays gastric emptying and has the potential to impact absorption of oral medicines. In clinical pharmacology trials, semaglutide did not affect the absorption of orally administered medications to any clinically relevant degree. Nonetheless, caution should be exercised when oral medications are taken with Ozempic.
Mounjaro	7.2 Oral Medications	Mounjaro delays gastric emptying and has the potential to impact the absorption of oral medications. Caution should be exercised when oral medications are taken with Mounjaro.
Zepbound	7.2 Oral Medications	Zepbound delays gastric emptying. Caution should be exercised. Monitor patients on oral medications dependent on threshold concentrations for efficacy and those with a narrow therapeutic index (for example, warfarin). Patients using oral hormonal contraceptives are advised to switch to a non-oral method, or add a barrier method, for 4 weeks after starting and for 4 weeks after each dose escalation.
Foundayo	7.3 Effect on Oral Medications	Foundayo delays gastric emptying and has the potential to impact absorption of oral medications. Patients using oral hormonal contraceptives are advised to switch to a non-oral method or add a barrier method for 30 days after starting and for 30 days after each dose escalation.

Two things stand out. First, the labels agree on the mechanism but not on the instruction, so the practical advice depends on the product. Second, the Zepbound and Foundayo labels are more specific than the others. They give a contraceptive time frame, Zepbound names warfarin as an example, and Foundayo includes limits on specific drugs.

What the studies in the labels measured

The clinical pharmacology sections give the data behind the warnings. They show that the effect is real but varies by drug and by dose, and that it is usually largest at the start.

Tirzepatide (Zepbound and Mounjaro)

The Zepbound label (section 12.3) says the impact of tirzepatide on gastric emptying was greatest after a single 5 mg dose and diminished after subsequent doses. After a first 5 mg dose, the maximum concentration (Cmax) of acetaminophen was reduced by 55% and the time to peak was about an hour later. After coadministration at week 6 with tirzepatide 15 mg, the label reports no meaningful impact on acetaminophen Cmax or time to peak, and overall acetaminophen exposure (AUC) was not influenced.

For a combined oral contraceptive taken with a single 5 mg dose of tirzepatide, the label reports that mean Cmax of ethinyl estradiol, norgestimate and norelgestromin was reduced by 59%, 66% and 55%, and mean AUC by 20%, 21% and 23%, with a delay in time to peak of 2.5 to 4.5 hours. That is the data behind the contraceptive advice in section 7.2. Our article on GLP-1 contraception and pregnancy labeling covers what the labels say about pregnancy and why the contraception advice matters.

Semaglutide (Wegovy and Ozempic)

The Wegovy label presents a more mixed picture. In clinical pharmacology trials with the 1 mg weekly injection, semaglutide did not affect the absorption of orally administered medicines, the label says in section 7.2. For the semaglutide tablet, a drug interaction study found levothyroxine exposure (AUC) increased 33% (90% CI 1.25 to 1.42) when a single 600 microgram dose of levothyroxine was taken at the same time, with maximum exposure unchanged. The label therefore says to monitor the effects of oral medicines taken with Wegovy and to consider extra clinical or laboratory monitoring for narrow-therapeutic-index drugs.

Section 12.3 also lists drugs where no clinically significant difference was observed when taken with semaglutide: lisinopril, S-warfarin, R-warfarin, metformin, digoxin, ethinyl estradiol, levonorgestrel, furosemide and rosuvastatin. In the same section, no clinically significant difference in semaglutide levels was seen with omeprazole. These results come from the studies reported in the label and do not cover every medicine or every dose, so they do not make other drugs automatically safe to combine.

Orforglipron (Foundayo)

The Foundayo label says gastric emptying delay is largest after the first dose and diminishes over time. The effect on acetaminophen Cmax was largest after the first dose of 0.8 mg, when it was decreased by 28%, and the effect diminished with repeated dosing at 17.2 mg. The label also states that the effect of Foundayo on absorption of oral contraceptives has not been evaluated in a clinical trial; the contraceptive advice is based on the expectation that delayed gastric emptying may affect absorption.

Foundayo has drug-specific rules that injections do not

Because orforglipron is a small-molecule tablet processed by liver enzymes and transporters, the Foundayo label includes interaction tables that the peptide injection labels do not. These are worth knowing about if you take other regular medicines.

• Strong CYP3A4 inhibitors. The maximum Foundayo dosage is 9 mg once daily when used with a strong CYP3A4 inhibitor. The label says to avoid strong CYP3A4 inhibitors that also inhibit OATP1B (ritonavir is the example given), because they are expected to significantly increase Foundayo concentrations and the risk of adverse reactions.
• Strong CYP3A4 inducers. The label says to avoid concomitant use, because induction decreases Foundayo exposure and may reduce its effectiveness.
• Moderate CYP3A4 inducers. The label says to monitor effectiveness and escalate the dosage as needed.
• Simvastatin. Do not exceed simvastatin 20 mg once daily when used with Foundayo. The label reports that coadministration increased exposure of the active metabolite simvastatin acid two-fold, which could be clinically meaningful at the highest simvastatin dose.
• Insulin and sulfonylureas. When starting Foundayo, consider reducing the dose of insulin or insulin secretagogues, because of the risk of hypoglycemia.

The label does not list every inhibitor or inducer by name beyond the examples it gives, so the practical step is to ask a pharmacist to check your complete list against the label. That is a service pharmacies routinely provide.

Wegovy tablets: the timing rules are about the tablet itself

A related instruction is easy to confuse with an interaction. The Wegovy tablet label says to take the tablet on an empty stomach in the morning with water (up to 4 ounces), to avoid other liquids, and to wait at least 30 minutes before eating, drinking beverages or taking other oral medicines. This addresses how the tablet itself is absorbed. The same 30-minute gap applies to your other morning pills, which is a practical point if you take medicines such as thyroid replacement first thing. Because the label reports increased levothyroxine exposure with the tablet, anyone taking levothyroxine should raise the timing and monitoring with their prescriber rather than rearranging doses alone. Our walk-through of how to take the Wegovy pill covers the routine in more detail.

Insulin and sulfonylureas: an interaction of a different kind

The interaction that the labels treat most firmly is pharmacodynamic rather than about absorption: GLP-1 medicines lower blood glucose, so using them with insulin or a sulfonylurea increases the risk of hypoglycemia. Wegovy, Zepbound and Foundayo each say to consider lowering the dose of the insulin or sulfonylurea when starting. We cover the label language and the trial rates in a separate article on GLP-1 medicines and low blood sugar.

Before surgery or a procedure

Delayed gastric emptying has another consequence the labels address: rare postmarketing reports of pulmonary aspiration in patients who had residual gastric contents during general anesthesia or deep sedation despite reported preoperative fasting. The Foundayo label, for example, makes this link directly to delayed gastric emptying in section 5.9. That is a separate topic from drug interactions, and our guide to GLP-1 medicines before surgery and anesthesia covers it.

What to do with this information

1. Make one complete list. Include prescriptions, over-the-counter medicines, vitamins and supplements, with doses and times of day.
2. Ask a pharmacist to run it against the label for your GLP-1 product. They can check narrow-therapeutic-index drugs and, for Foundayo, the CYP3A4 and simvastatin rules.
3. Pay extra attention at the start and after each dose increase. The studies in the labels show the stomach effect is largest early, and the contraceptive advice is tied to initiation and escalation.
4. Do not change doses or timing on your own. Monitoring decisions, such as extra blood tests for warfarin or thyroid medicines, belong to your prescriber.
5. Tell every clinician you see that you take a GLP-1 medicine. That includes dentists, surgeons and urgent care.

We have deliberately left prices out of this article, because the question here is safety information from the labels, not cost.

Common mistakes

• Assuming the injection and tablet labels say the same thing. The Wegovy label covers both, and contains tablet-specific data such as the levothyroxine finding.
• Treating “no clinically significant difference” as a guarantee. It describes specific studies, not all drugs.
• Forgetting non-oral contraception advice. The Zepbound and Foundayo labels advise a switch or barrier method for set periods after starting and after each dose escalation.
• Taking Foundayo with a strong CYP3A4 inhibitor or inducer without telling anyone. The label sets a cap or says to avoid the combination.
• Self-adjusting a diabetes medicine. The labels say to consider reducing doses, which is a prescriber decision.

Questions people ask

Medical disclaimer. This article is informational, was prepared by the GLP-1.Reviews editorial team from the public sources listed above, and is not medical advice. Interaction guidance depends on your full medicine list and health history, which this article cannot assess. Talk to your prescriber or pharmacist about your own treatment, and see our medical disclaimer and editorial standards.

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