GLP-1 Drug Interactions: What Section 7 of Each FDA Label Says

This is a reference page. Its only job is to reproduce, accurately and with attribution, the drug interaction statements in the FDA-approved United States prescribing information for six GLP-1 receptor agonist products: Ozempic (semaglutide injection), Wegovy (semaglutide injection and tablets), Rybelsus (semaglutide tablets), Mounjaro and Zepbound (tirzepatide injection) and Saxenda (liraglutide injection). Each copy was read on DailyMed, the National Library of Medicine's mirror of current FDA labeling, accessed 14 September 2026. Where a label's own revision date is printed here, it is the date on that label's first page.

It is not medical advice. It does not tell you which medications can be taken together, whether a dose of anything should change, or what monitoring you need. Every statement quoted below is written by the manufacturer for a prescribing clinician, and the verbs in those sentences — "consider," "monitor," "advise" — are addressed to that clinician. The only reason to transcribe them here is so that somebody keeping their own medication record can see what the label actually says and where, rather than what a forum post says it says.

The page is also deliberately limited to Section 7, Drug Interactions, plus the two other label sections it cross-references: Section 8.3 on contraception and Section 12.3 on the underlying pharmacokinetic studies. It does not cover the Victoza, Trulicity, Bydureon BCise or Foundayo labels; those documents have their own Section 7 and should be read in their own right. It does not cover alcohol, supplements or foods, because the labels' interaction sections do not. And it does not cover the anesthesia and aspiration warning, which lives in Section 5 of each label and has its own page: surgery or endoscopy on a GLP-1.

If you want guidance rather than reference material, the right next step is the pharmacist who dispenses your prescriptions and the prescriber who wrote them. Interaction screening against your full medication list is something a pharmacist does routinely, and it is the single most useful thing to ask for.

The first thing every one of these labels says about interactions is the same. The Ozempic label, Section 7.2, reads: "OZEMPIC causes a delay of gastric emptying, and thereby has the potential to impact the absorption of concomitantly administered oral medications." The Wegovy label uses the same wording with its own name. The Mounjaro and Zepbound labels state it as "delays gastric emptying and thereby has the potential to impact the absorption of concomitantly administered oral medications." The Rybelsus label says semaglutide causes "a delay of gastric emptying and thereby has the potential to impact the absorption of other oral drugs." The Saxenda label, whose Section 7 has only one subsection, 7.1 Oral Medications, says the same of liraglutide (all via DailyMed, accessed 14 September 2026).

What the labels say next is where they diverge, and the divergence is worth reading carefully. The semaglutide injection labels add a reassurance: the Ozempic label states that "in clinical pharmacology trials, semaglutide did not affect the absorption of orally administered medications to any clinically relevant degree," and then, "nonetheless, caution should be exercised." Section 12.3 of the same label names the drugs studied — metformin and an oral contraceptive (ethinylestradiol/levonorgestrel) at steady state, and warfarin, digoxin and atorvastatin after a single dose — and concludes that "no clinically relevant drug-drug interaction with semaglutide was observed based on the evaluated medications." The Saxenda label makes a parallel statement for liraglutide about "the tested orally administered medications" and asks the clinician to "monitor for potential consequences of delayed absorption."

The tirzepatide labels contain no such reassurance. Mounjaro and Zepbound, Section 7.2, move straight from the mechanism to a caution — "Caution should be exercised when oral medications are concomitantly administered" — and then to two named categories: medications "dependent on threshold concentrations for efficacy" and those "with a narrow therapeutic index (e.g., warfarin)." Section 8.3 of the Mounjaro label adds the detail that makes sense of the whole section: the delay in gastric emptying "is largest after the first dose and diminishes over time." Section 12.3 illustrates it with acetaminophen, whose peak concentration was reduced by 50% after a first dose of tirzepatide but showed "no meaningful impact" by week four, with overall exposure unaffected.

For a reader, the point of this section is not a list of safe and unsafe drugs — the labels do not provide one. It is that the labels treat the first dose and each escalation as the moments that matter, and that a record showing when those moments happened is the thing a pharmacist can actually use. The pharmacokinetic background on each product's own page, such as the Mounjaro label reference, explains why exposure to the GLP-1 itself builds over the first month.

This is the most specific interaction statement on any of the six labels, and it appears only on the two tirzepatide labels. Section 7.2 of the Mounjaro label, revised 8/2026, reads in full: "Advise patients using oral hormonal contraceptives to switch to a non-oral contraceptive method or add a barrier method of contraception for 4 weeks after initiation and for 4 weeks after each dose escalation with MOUNJARO. Hormonal contraceptives that are not administered orally should not be affected." The Zepbound label, also revised 8/2026, carries the same instruction with a slightly different word order: "switch to a non-oral contraceptive method, or add a barrier method of contraception for 4 weeks after initiation with ZEPBOUND and for 4 weeks after each dose escalation" (via DailyMed, accessed 14 September 2026).

Section 8.3 of the Mounjaro label gives the reasoning: "Use of MOUNJARO may reduce the efficacy of oral hormonal contraceptives due to delayed gastric emptying. This delay is largest after the first dose and diminishes over time." Section 12.3 reports the study behind it. After a combined oral contraceptive containing ethinyl estradiol and norgestimate was given with a single first dose of tirzepatide, the label states that mean peak concentration of ethinyl estradiol, norgestimate and norelgestromin "was reduced by 59%, 66%, and 55%, while mean AUC was reduced by 20%, 21%, and 23%, respectively," with peak timing delayed by "2.5 to 4.5 hours." Those are the label's figures for a single first dose; the label does not report the same measurements at steady state, and this page does not extrapolate them.

The semaglutide labels say something different, and the difference is easy to miss. Neither the Ozempic nor the Wegovy label carries a contraceptive instruction in Section 7. The Ozempic label's Section 12.3 lists an oral contraceptive (ethinylestradiol/levonorgestrel) among the drugs assessed at steady state and reports no clinically relevant interaction; the Rybelsus label's Section 12.3 lists ethinyl estradiol and levonorgestrel among drugs with "no clinically significant differences" in pharmacokinetics when taken with semaglutide tablets. The Saxenda label's Section 7 does not mention contraceptives at all. So the four-week statement belongs to tirzepatide and to nobody else on this page; that is a fact about the labels, not a ranking of the products.

What a record can hold here is straightforward, because the label anchors its statement to two kinds of date: the day of initiation and the day of each dose escalation. Those are exactly the events described in how to record a GLP-1 dose change. Which contraceptive method is appropriate, and for whom, is a conversation with a prescriber; the label's instruction is written to that prescriber, and this page repeats it only so the wording is available verbatim.

Five of the six labels open Section 7 with insulin and insulin secretagogues, the class that includes sulfonylureas. The Ozempic label, Section 7.1, states the mechanism first: "OZEMPIC stimulates insulin release in the presence of elevated blood glucose concentrations. Patients receiving OZEMPIC in combination with an insulin secretagogue (e.g., sulfonylurea) or insulin may have an increased risk of hypoglycemia, including severe hypoglycemia." It then says: "When initiating OZEMPIC, consider reducing the dose of concomitantly administered insulin secretagogue (such as sulfonylureas) or insulin to reduce the risk of hypoglycemia." The Rybelsus label states the same in the same words for semaglutide tablets (via DailyMed, accessed 14 September 2026).

The Wegovy label, Section 7.1, is worded for a weight-management product and contains a sentence the diabetes labels do not: "WEGOVY lowers blood glucose and can cause hypoglycemia. The risk of hypoglycemia is increased when WEGOVY is used concomitantly with insulin or insulin secretagogues (e.g., sulfonylureas). The addition of WEGOVY in patients treated with insulin has not been evaluated." The Zepbound label opens its Section 7.1 with "ZEPBOUND lowers blood glucose" and continues with the same consider-reducing-the-dose language, as does the Mounjaro label.

The Saxenda label is the exception in structure rather than substance. Its Section 7 contains only the oral medications subsection; the insulin and sulfonylurea statement sits instead in Section 5.4, Warnings and Precautions, which states that adult patients with type 2 diabetes "on an insulin secretagogue (e.g., sulfonylurea) or insulin may have an increased risk of hypoglycemia." A reader searching only Section 7 of the Saxenda label would miss it, which is one reason this page names the section for every quotation.

The verb in every one of these sentences is "consider," and the subject is the prescriber. The label describes a risk and hands the decision about the other medication to the clinician who manages it. Nothing on this page changes that. What a person on a GLP-1 together with insulin or a sulfonylurea can do is keep the record the clinician will ask for: which products, when each was started, and when symptoms occurred — the same record described in the GLP-1 and type 2 diabetes guide. Anyone who thinks they are experiencing hypoglycemia should contact their prescriber; that is not something a reference page or a tracking app can assess.

Two named drugs appear in these labels' interaction sections, and they appear for different reasons.

Warfarin is named as an example. Section 7.2 of the Mounjaro and Zepbound labels reads: "Monitor patients on oral medications dependent on threshold concentrations for efficacy and those with a narrow therapeutic index (e.g., warfarin) when concomitantly administered." The Wegovy and Rybelsus labels do not name warfarin in Section 7 but state the same category: the Wegovy label asks the clinician to "consider increased clinical or laboratory monitoring for medications that have a narrow therapeutic index or that require clinical monitoring," and the Rybelsus label uses near-identical wording. The Ozempic label, by contrast, reports in Section 12.3 that S-warfarin and R-warfarin were among the drugs studied after a single dose and that no clinically relevant interaction was observed; the Rybelsus label's Section 12.3 lists S-warfarin and R-warfarin among drugs with "no clinically significant differences" in pharmacokinetics with semaglutide tablets (via DailyMed, accessed 14 September 2026).

A word about INR, because it is the term readers search for. The international normalized ratio is the blood test used to monitor warfarin, and none of the six labels on this page uses the term. What the labels ask for is "monitoring" and "laboratory monitoring" of narrow-therapeutic-index drugs; which test, how often and what result would prompt a change are decided by the clinician managing the anticoagulant. This page reproduces the labels' words and does not add its own.

Levothyroxine is named because of a measurement. Section 7.2 of the Rybelsus label, revised 1/2026, states: "Levothyroxine exposure was increased 33% (90% CI: 1.25 to 1.42) when administered with semaglutide tablets in a drug interaction study." Section 12.3 of the same label specifies that this was total thyroxine AUC, adjusted for endogenous levels, after a single dose of levothyroxine with semaglutide tablets. The Wegovy label, revised 6/2026, repeats the finding in its own Section 7.2 — "In a drug interaction study with the semaglutide tablet, levothyroxine exposure was increased 33% (90% CI: 1.25-1.42)" — because the Wegovy label now covers both the injection and the Wegovy tablet, the tablet study appears there too. The Ozempic injection label's Section 7 does not mention levothyroxine, and neither do the Mounjaro, Zepbound or Saxenda labels. The oral product's absorption story, covered on the Rybelsus label reference, is the reason a tablet-specific interaction study exists at all.

Every statement above is anchored to something a record can hold: a start date, an escalation date, a list of other medications, a symptom with a time on it. None of it is anchored to a decision a reader can make alone. That division is the practical use of this page.

The list worth keeping is the complete one. Interaction screening only works against everything you take — prescription medications, over-the-counter products and supplements included — with the date each was started or changed. Pharmacists do this screening as a matter of routine, and it is the most direct way to have a question about any of the drugs named on this page answered for your own circumstances rather than in the abstract. If you take an oral medication that your prescriber has described as needing monitoring, the date of your GLP-1 initiation and of each escalation is the single most useful detail to have written down, because those are the moments the tirzepatide labels single out.

GLP-1 Tracker is the practical layer for that record on iPhone, free: each logged dose with its date, the dose-change history, your weight trend and your own notes, held on the device. It does not contain an interaction checker, it does not know what else you take unless you write it in a note, and it never flags anything as significant. Its job is to make the timeline accurate when a pharmacist or prescriber asks for it. The structure of that conversation is covered in how to prepare a GLP-1 summary for your doctor, and the questions worth asking are collected in questions to ask at your GLP-1 follow-up.

Labels are revised — all six labels on this page carry 2026 revision dates — which is why the access date is printed beside every quotation. If a sentence here ever conflicts with the current label on DailyMed, the current label is correct and this page is out of date.