GLP-1 drug interactions
What the labels say, and where they say nothing
10 of 10 shown
The combined pill or any oral contraceptive
MedicationThis is the one that splits by molecule. Tirzepatide and orforglipron carry an explicit contraception warning; semaglutide does not.
- TirzepatideZepbound, MounjaroThe label tells you to do something
Switch to a non-oral contraceptive method, or add a barrier method, for 4 weeks after starting and for 4 weeks after each dose escalation. Non-oral hormonal contraceptives are not expected to be affected.
Zepbound label §7.1–7.2
- OrforglipronFoundayoThe label tells you to do something
The same instruction, for 30 days after starting and 30 days after each dose escalation.
Foundayo label §7.1–7.3
- SemaglutideWegovy, Ozempic, RybelsusStudied, no meaningful effect
No contraception warning. The label's clinical pharmacology reports that semaglutide did not meaningfully change exposure to ethinylestradiol or levonorgestrel.
Wegovy label §12.3
Insulin, or a sulfonylurea
MedicationThe one interaction every GLP-1 label addresses, and the only one that can be an emergency.
- SemaglutideWegovy, Ozempic, RybelsusThe label tells you to do something
Risk of hypoglycaemia is increased. When starting, the label says to consider reducing the dose of the insulin or sulfonylurea.
Wegovy label §7.1–7.2
- TirzepatideZepbound, MounjaroThe label tells you to do something
The same: consider reducing the insulin or sulfonylurea dose when starting.
Zepbound label §7.1–7.2
- OrforglipronFoundayoThe label tells you to do something
The same consideration applies.
Foundayo label §7.1–7.3
Warfarin, or another narrow-therapeutic-index drug
MedicationNot a chemical interaction — a timing one. Slowed stomach emptying changes when a drug is absorbed, which matters most where the dose window is narrow.
- TirzepatideZepbound, MounjaroMonitor or use caution
Monitor patients on oral medications that depend on threshold concentrations, and those with a narrow therapeutic index, warfarin being the label's own example.
Zepbound label §7.1–7.2
- SemaglutideWegovy, Ozempic, RybelsusMonitor or use caution
Monitor the effects of oral medications taken alongside it. For oral semaglutide the label asks for increased clinical or laboratory monitoring with narrow-therapeutic-index drugs.
Wegovy §7.2; Rybelsus §7.2
- OrforglipronFoundayoMonitor or use caution
Delays gastric emptying with the same potential to affect oral absorption.
Foundayo label §7.1–7.3
Simvastatin
MedicationA specific dose ceiling, and it applies to one molecule only.
- OrforglipronFoundayoThe label tells you to do something
Do not exceed simvastatin 20 mg once daily when taken with it.
Foundayo label §7.1–7.3
- TirzepatideZepbound, MounjaroMonitor or use caution
No statin-specific instruction beyond the general oral-absorption caution.
Zepbound label §7.1–7.2
- SemaglutideWegovy, Ozempic, RybelsusStudied, no meaningful effect
No specific ceiling. The label's pharmacology reports atorvastatin exposure was not meaningfully changed.
Wegovy label §12.3
Strong CYP3A4 inhibitors or inducers
MedicationOnly the small molecule has real enzyme interactions. The peptides essentially do not.
- OrforglipronFoundayoThe label tells you to do something
Maximum dose is 9 mg daily with a strong CYP3A4 inhibitor, and concomitant use is to be avoided where the inhibitor also inhibits OATP1B. Avoid strong CYP3A4 inducers; with moderate inducers, monitor effectiveness and escalate as needed.
Foundayo label §7.1–7.3
- SemaglutideWegovy, Ozempic, RybelsusNot addressed on any label
No CYP interaction warning. Semaglutide is a peptide and is not metabolised through this pathway in a way the label flags.
- TirzepatideZepbound, MounjaroNot addressed on any label
No CYP interaction warning, for the same reason.
Alcohol
EverydayNo approved GLP-1 label carries an alcohol interaction warning. That is an absence of guidance, not a clearance.
- SemaglutideWegovy, Ozempic, RybelsusNot addressed on any label
Not addressed in the label's drug interactions section. There are real reasons to be careful — hypoglycaemia risk if you also take insulin or a sulfonylurea, and alcohol's own effect on a slowed stomach — but none of that is a labelled interaction.
- TirzepatideZepbound, MounjaroNot addressed on any label
Not addressed in the label's drug interactions section. There are real reasons to be careful — hypoglycaemia risk if you also take insulin or a sulfonylurea, and alcohol's own effect on a slowed stomach — but none of that is a labelled interaction.
- OrforglipronFoundayoNot addressed on any label
Not addressed in the label's drug interactions section. There are real reasons to be careful — hypoglycaemia risk if you also take insulin or a sulfonylurea, and alcohol's own effect on a slowed stomach — but none of that is a labelled interaction.
Coffee and caffeine
EverydayNot addressed on any label.
- SemaglutideWegovy, Ozempic, RybelsusNot addressed on any label
No approved label addresses caffeine. Pages that give you a confident answer here are not reading a label.
- TirzepatideZepbound, MounjaroNot addressed on any label
No approved label addresses caffeine. Pages that give you a confident answer here are not reading a label.
- OrforglipronFoundayoNot addressed on any label
No approved label addresses caffeine. Pages that give you a confident answer here are not reading a label.
Ibuprofen and other NSAIDs
MedicationNo specific labelled interaction, but they fall under the general oral-absorption caution.
- SemaglutideWegovy, Ozempic, RybelsusNot addressed on any label
No NSAID-specific interaction is listed. As an oral medication it sits inside the general caution about delayed gastric emptying affecting absorption.
- TirzepatideZepbound, MounjaroNot addressed on any label
No NSAID-specific interaction is listed. As an oral medication it sits inside the general caution about delayed gastric emptying affecting absorption.
- OrforglipronFoundayoNot addressed on any label
No NSAID-specific interaction is listed. As an oral medication it sits inside the general caution about delayed gastric emptying affecting absorption.
Vitamins and supplements
SupplementNot addressed, and not reviewed by anyone in the way a drug is.
- SemaglutideWegovy, Ozempic, RybelsusNot addressed on any label
No approved label addresses supplements. They are also not assessed for interactions the way prescription medicines are, so the absence of a warning here carries even less weight than usual.
- TirzepatideZepbound, MounjaroNot addressed on any label
No approved label addresses supplements. They are also not assessed for interactions the way prescription medicines are, so the absence of a warning here carries even less weight than usual.
- OrforglipronFoundayoNot addressed on any label
No approved label addresses supplements. They are also not assessed for interactions the way prescription medicines are, so the absence of a warning here carries even less weight than usual.
Another GLP-1, or a compounded version
MedicationEvery label rules this out explicitly. It is the clearest prohibition of the set.
- SemaglutideWegovy, Ozempic, RybelsusThe label tells you to do something
Do not use with other semaglutide-containing products or any other GLP-1 receptor agonist. Stated in the Limitations of Use.
Wegovy label §1
- TirzepatideZepbound, MounjaroThe label tells you to do something
Coadministration with other tirzepatide-containing products or any GLP-1 receptor agonist is not recommended.
Zepbound label §1
- OrforglipronFoundayoThe label tells you to do something
The same limitation applies.
Foundayo label §1
Every entry above is read from an approved FDA label, cited by section. Where a label says nothing, this page says nothing — see compounded products, which have no label of their own and therefore none of this.
Direct answer
What you need to know
Evidence strength: StrongThe interaction that matters most is not on every GLP-1 label — it is on some of them. Tirzepatide tells patients using oral contraceptives to add a barrier method for four weeks after starting and after every dose escalation. Orforglipron says the same for thirty days. Semaglutide carries no such warning at all. Beyond that, the labels are short: hypoglycaemia with insulin or a sulfonylurea, caution with oral medications generally, and for orforglipron a set of enzyme interactions the peptides do not have.
Key takeaways
- The contraception warning follows the molecule, not the brand — and switching products can quietly acquire it.
- Orforglipron is the only one with real CYP interactions, because it is a small molecule rather than a peptide.
- Every label prohibits combining a GLP-1 with another GLP-1, compounded ones included.
- 4 of the 10 things people ask about here are addressed by no label at all.
Important limitation: A label’s interactions section is not a complete list of everything that can interact — it is what the manufacturer studied and the FDA reviewed. Silence means untested far more often than it means safe, and this page can only report the silence, not resolve it. It also cannot see your actual medication list, which is the thing that determines your answer.
Next action: Take your full medication list, including anything over the counter, to a pharmacist. Checking it against a real interaction database takes about a minute and costs nothing. If you are about to switch products, ask specifically about contraception.
Primary sources: FDA — Zepbound label, FDA — Wegovy label
General education, not medical advice. Do not start, stop, or change any medication based on this page.
The split nobody mentions
Most pages on this subject treat “GLP-1” as one thing. On interactions, that is where the useful information is lost, because the labels do not agree with each other.
| Molecule | Products | What the label says |
|---|---|---|
| Tirzepatide | Zepbound, Mounjaro | Switch to a non-oral method or add a barrier method for 4 weeks after starting, and 4 weeks after each dose escalation. |
| Orforglipron | Foundayo | The same, for 30 days. |
| Semaglutide | Wegovy, Ozempic, Rybelsus | No warning. The label reports semaglutide did not meaningfully change ethinylestradiol or levonorgestrel exposure. |
Two things follow. A person on Zepbound climbing from 2.5 mg to 15 mg passes through five dose escalations, each opening its own four-week window. And a person moving from Wegovy to Zepbound acquires a warning they never had, with nothing in the switch to flag it. Our titration tracker shows where those escalations fall.
A label saying nothing about something is not the same as a label saying it is fine. Most of this page is the first kind.
Why the answer is short, and honest about it
The peptide GLP-1s barely interact with anything in the classical sense. They are not processed through the liver enzyme pathways that generate most drug interactions, which is why the labels’ interaction sections run to a few paragraphs rather than pages. What they do instead is slow the stomach, and that is a timing problem rather than a chemical one: it can change when an oral drug is absorbed, which matters most where the dose window is narrow.
Orforglipron is the exception, and for a structural reason. It is a small molecule rather than a peptide, so it behaves like an ordinary oral drug: a dose cap with strong CYP3A4 inhibitors, avoidance of strong inducers, and a simvastatin ceiling of 20 mg. If you have been told “GLP-1s don’t really interact with anything”, that sentence was true before this product existed.
What no label addresses
Alcohol, caffeine, NSAIDs and supplements are all searched constantly, and no approved GLP-1 label lists any of them as an interaction. Pages that answer these confidently are not quoting a label, because there is nothing to quote.
We are not going to fill that gap with something plausible. What we can say is why the silence exists: an interactions section reports what the manufacturer studied and the FDA reviewed, and nobody runs interaction trials on coffee. The absence is about what was tested, not about what is safe.
When this stops being a web-page question
If you take insulin or a sulfonylurea, the hypoglycaemia interaction is real, immediate, and on every label — that is a conversation to have before your first dose, not after a bad episode. The same applies if you take warfarin or anything else where a specific blood level matters.
Common questions
Do GLP-1 medications affect birth control?
It depends which one you take, and this is the most consequential difference on the page. Tirzepatide (Zepbound, Mounjaro) tells patients on oral contraceptives to switch to a non-oral method or add a barrier method for 4 weeks after starting and for 4 weeks after every dose escalation. Orforglipron (Foundayo) says the same for 30 days. Semaglutide (Wegovy, Ozempic, Rybelsus) carries no such warning, and its label reports that semaglutide did not meaningfully change ethinylestradiol or levonorgestrel exposure. Non-oral hormonal contraceptives are not expected to be affected by any of them.
Can I drink alcohol on a GLP-1?
No approved GLP-1 label lists alcohol as an interaction. That is an absence of guidance rather than a clearance. There are real reasons for care that sit outside the interactions section — hypoglycaemia risk if you also take insulin or a sulfonylurea, and alcohol on a stomach that is emptying slowly — but anyone giving you a confident labelled answer here is not reading a label.
Why does the answer change depending on which GLP-1 I take?
Because the labels are written per product and the molecules genuinely differ. Orforglipron is a small molecule rather than a peptide, so it is the only one of the six with real enzyme interactions — a dose cap with strong CYP3A4 inhibitors and a simvastatin ceiling. Tirzepatide acts on a second receptor and carries a contraception warning semaglutide does not. Treating 'GLP-1' as one thing is exactly how people miss these.
I switched from Wegovy to Zepbound. Does anything change?
Yes, and nothing about the switch announces it. If you take an oral contraceptive, you have moved from a product with no contraception warning to one that asks for a barrier method for 4 weeks — and again after every dose increase, which on Zepbound can mean several separate 4-week windows as you climb. Raise it with your prescriber before the first dose.
Is it safe to take ibuprofen or paracetamol with a GLP-1?
Neither is listed as a specific interaction on any approved GLP-1 label. Both are oral medications, so they sit inside the general caution that delayed gastric emptying can affect how oral drugs are absorbed. That caution is about timing and absorption rather than a chemical clash. If you take something where the exact blood level matters, that is the case the labels ask prescribers to monitor.
What about taking two GLP-1s, or adding a compounded one?
Every label rules this out explicitly. Wegovy's Limitations of Use says not to use it with other semaglutide-containing products or any other GLP-1 receptor agonist; Zepbound and Foundayo say the same. This is the clearest prohibition in the set, and it includes adding a compounded product alongside a branded one.
Sources
Each source below supports specific statements on this page. We cite the strongest available authority and verify against the current version before publishing.
- ZEPBOUND (tirzepatide) injection — Prescribing InformationU.S. Food & Drug AdministrationSupports: Section 7.2 — the instruction to switch to a non-oral contraceptive or add a barrier method for 4 weeks after starting and after each dose escalation, the narrow-therapeutic-index monitoring, and the insulin/sulfonylurea consideration.
- MOUNJARO (tirzepatide) injection — Prescribing InformationEli Lilly, via DailyMedSupports: The same contraception instruction on the other tirzepatide product, confirming it follows the molecule rather than the brand.
- WEGOVY (semaglutide) injection — Prescribing InformationU.S. Food & Drug AdministrationSupports: Sections 7.1–7.2 and the clinical pharmacology in 12.3 reporting that semaglutide did not meaningfully change ethinylestradiol, levonorgestrel, warfarin, digoxin, atorvastatin or metformin exposure — the absence that makes the contraception split real.
- FOUNDAYO (orforglipron) tablets — Prescribing InformationEli Lilly, via DailyMedSupports: Sections 7.1–7.3 — the CYP3A4 dose cap, the simvastatin ceiling, and the 30-day contraception instruction.
- FDA-approved prescribing information (drug labels)DailyMed, U.S. National Library of MedicineSupports: The current prescribing information for each product, which governs over this page.
This page is general education, not medical advice. Talk to your own healthcare provider about your situation before starting, stopping, or changing any medication.