Kyleena Drug Interactions: What to Avoid and What to Tell Your Doctor

One of the advantages of Kyleena over oral contraceptives is that drug interactions are less of a concern — because the hormone is released locally in the uterus rather than absorbed systemically in large amounts. However, some medications and supplements can still affect how well Kyleena works or interact with the levonorgestrel it releases. Here's what you need to know before starting Kyleena in 2026.

How Drug Interactions Work With Kyleena

Most drug interactions with hormonal contraceptives involve the CYP3A4 enzyme system in the liver. When a drug induces (speeds up) the CYP3A4 enzyme, it causes the liver to break down levonorgestrel faster — which can lower LNG blood levels and potentially reduce contraceptive effectiveness. Because Kyleena works primarily through local uterine effects (not requiring high systemic LNG levels), it may be less affected by these interactions than oral pills — but the risk isn't zero.

Medications That May Reduce Kyleena's Effectiveness

The following CYP3A4 inducers can increase the breakdown of levonorgestrel and potentially reduce Kyleena's contraceptive effectiveness:

Anticonvulsants (Seizure Medications)

Phenytoin (Dilantin) — A strong CYP3A4 inducer; may significantly reduce LNG levels

Carbamazepine (Tegretol) — Strong CYP3A4 inducer; commonly used for epilepsy, bipolar disorder, and neuropathic pain

Phenobarbital — Barbiturate anticonvulsant; induces liver enzymes that metabolize hormones

Oxcarbazepine (Trileptal) — Moderate CYP inducer; may lower hormone levels

Antibiotics

There is a long-standing concern about whether antibiotics reduce hormonal contraceptive effectiveness. Current evidence suggests that most antibiotics do NOT significantly reduce the effectiveness of Kyleena — unlike with oral contraceptives where gut flora interactions could reduce absorption. However, one important exception exists:

Rifampin (Rifadin) — A potent CYP3A4 inducer used for tuberculosis; significantly speeds up LNG metabolism and may reduce contraceptive effectiveness. If you are on rifampin, discuss backup contraception with your provider.

HIV Antiretroviral Medications (ARVs)

Several HIV antiretroviral medications can interact with levonorgestrel:

Protease inhibitors (e.g., ritonavir, lopinavir) and non-nucleoside reverse transcriptase inhibitors (e.g., efavirenz, nevirapine) — Can either induce or inhibit CYP3A4 and potentially alter LNG levels. If you are on ARV therapy, inform your provider and gynecologist so they can assess whether additional contraception is needed.

Herbal Supplements

St. John's Wort (Hypericum perforatum) — A widely used herbal remedy for mood disorders that is a potent CYP3A4 inducer. It can significantly reduce levonorgestrel blood levels and may decrease Kyleena's contraceptive protection. If you take St. John's Wort regularly, discuss backup contraception with your provider.

Medications That Do NOT Significantly Interact With Kyleena

The vast majority of common medications do not meaningfully interact with Kyleena. Here are some that patients often ask about:

NSAIDs (ibuprofen, naproxen): Occasional or regular use of NSAIDs does not reduce Kyleena's contraceptive effectiveness. Some research suggests regular use may slightly reduce the period-lightening benefit, but this does not affect pregnancy prevention.

Most common antibiotics (amoxicillin, azithromycin, doxycycline, etc.): Do not meaningfully affect Kyleena's effectiveness. The 1970s-era concern about antibiotics and contraceptive failure was based on oral pill data and does not apply to IUDs.

Antidepressants (SSRIs, SNRIs): Do not interact with Kyleena's contraceptive effectiveness. However, some patients report mood changes on Kyleena — this may be worth discussing with your prescribing provider separately.

Blood pressure medications, statins, diabetes medications, thyroid medications: No clinically significant interactions with Kyleena have been reported for most medications in these classes.

What to Tell Your Doctor Before Getting Kyleena

Before your Kyleena insertion appointment, tell your provider about all medications you take — including over-the-counter drugs, vitamins, and herbal supplements. Pay particular attention to disclosing:

Any anticonvulsant or seizure medications

Rifampin or rifabutin (TB medications)

HIV antiretroviral medications

St. John's Wort (even occasional use)

Any new medications prescribed after Kyleena is placed

The Bottom Line on Kyleena Drug Interactions

Because Kyleena works locally in the uterus, it has fewer clinically significant drug interactions than oral contraceptives. The main concerns are potent CYP3A4 inducers — particularly rifampin, certain anticonvulsants, and St. John's Wort. For most other medications, Kyleena remains highly effective with no additional precautions needed. Always tell your prescribing provider about all medications you take. For more on what to watch for after insertion, see our guide on Kyleena side effects.

Ready to find a provider near you for your Kyleena consultation? medfinder can help you locate the right provider quickly.