What Not to Take With Desogestrel: Key Drug Interactions Explained

October 10, 2025 •

4 min read

Hormonal contraceptive failure in women using certain medications, such as some antiepileptic drugs (AEDs), is a recognized risk due to drug interactions. For those taking desogestrel, a progestogen-only contraceptive, or a combined pill containing desogestrel, understanding potential interactions is critical for maintaining effectiveness and avoiding unwanted side effects. Certain substances can accelerate the metabolism of desogestrel, while others can interfere with its absorption, compromising its function.

Quick Summary

Several medications and supplements can significantly interact with desogestrel, potentially reducing its contraceptive efficacy. Interactions involve liver enzyme-inducing drugs like certain anticonvulsants, specific antibiotics, and herbal remedies such as St. John's wort. Some foods, like grapefruit, and substances like activated charcoal can also be problematic. Understanding these risks is crucial for anyone using desogestrel-based contraception.

Key Points

Avoid strong enzyme inducers: Medications like some anticonvulsants (phenytoin, carbamazepine) and antibiotics (rifampin) can significantly reduce desogestrel's effectiveness.
Be cautious with supplements: Herbal remedies such as St. John's wort and products containing activated charcoal are known to interfere with hormonal contraceptives and should be avoided.
Limit or avoid grapefruit products: Grapefruit juice can alter drug metabolism, so its consumption should be discussed with a doctor while taking desogestrel.
Inform healthcare providers: Always disclose all medications, including over-the-counter drugs and supplements, to your doctor to prevent risky interactions.
Use backup contraception when necessary: If you must take an interacting medication, rely on a backup barrier method like condoms to ensure protection against pregnancy.
Manage HIV/HCV medications carefully: Certain treatments for HIV and Hepatitis C can interact with desogestrel, requiring specific guidance from a healthcare provider.

Understanding Desogestrel and Its Interactions

Desogestrel is a synthetic progestogen used in hormonal contraception, both in progestogen-only pills (mini-pills) and in combined oral contraceptives (COCs) with ethinyl estradiol. Its primary contraceptive action is to prevent ovulation, though it also thickens cervical mucus to block sperm and thins the uterine lining to prevent implantation. Drug interactions occur when other substances alter how desogestrel is processed by the body, typically in the liver. The most common mechanism involves a group of liver enzymes called cytochrome P450 (specifically CYP3A4). Some substances, called enzyme inducers, speed up the activity of these enzymes, causing desogestrel to be broken down and eliminated more quickly, thus lowering its concentration in the bloodstream. This can significantly reduce contraceptive protection.

Medications That Compromise Contraceptive Efficacy

Enzyme-Inducing Medications

Several prescription medications are known to act as potent liver enzyme inducers, which can lead to reduced desogestrel levels and an increased risk of contraceptive failure. If you are prescribed any of the following, a doctor will likely advise using a different form of contraception or a reliable backup method.

Anticonvulsants (Seizure Medications): Several older and some newer antiepileptic drugs are particularly known for this interaction. This includes:
- Carbamazepine (Tegretol)
- Phenytoin (Dilantin)
- Phenobarbital
- Primidone
- Felbamate
- Topiramate (Topamax)
Antibiotics: While the widespread belief that all antibiotics interfere with hormonal birth control is largely a myth, specific types are known to cause problems. The primary culprits are:
- Rifampin (Rifadin), used for tuberculosis
- Rifabutin
HIV and Hepatitis C Treatments: Certain antiretroviral and antiviral drugs can affect desogestrel levels. Examples include some protease inhibitors and non-nucleoside reverse transcriptase inhibitors like efavirenz. Cobicistat-boosted regimens should also be managed with caution.
Other Medications: Some other drugs, including bosentan (for pulmonary hypertension), griseofulvin (for fungal infections), and aprepitant (anti-nausea), are also documented to reduce desogestrel's effectiveness.

Supplements and Foods to Avoid

Natural products and dietary choices can also impact desogestrel's metabolism and absorption, warranting careful consideration.

Herbal Supplements

St. John's Wort: This popular supplement, often used for mood disorders, is a powerful enzyme inducer and can significantly reduce the efficacy of desogestrel. The MHRA advises avoiding this combination due to a risk of breakthrough bleeding and unwanted pregnancy.
Activated Charcoal: Used in some supplements for 'detox' or bloating, activated charcoal binds to substances in the digestive tract and can prevent the proper absorption of medications, including desogestrel. It's crucial to avoid taking it near the time you take your contraceptive pill.

Foods and Other Substances

Grapefruit Juice: Grapefruit contains compounds that inhibit the CYP3A4 enzyme, but the effect on hormonal contraceptives can be variable depending on the specific hormones. Some sources suggest it could increase levels of ethinyl estradiol (in combined pills) leading to more side effects, while others note it can alter desogestrel absorption. Given the uncertainty, many healthcare providers advise limiting or avoiding grapefruit and its juice while taking desogestrel.
Alcohol: While moderate alcohol consumption does not affect contraceptive effectiveness, heavy drinking can lead to missed or inconsistent pill-taking, thereby increasing the risk of pregnancy.

Comparison of Desogestrel Interactions


Interacting Substance	Type of Interaction	Potential Outcome	Recommended Action
Carbamazepine, Phenytoin	Liver enzyme induction	Reduces desogestrel levels, increasing pregnancy risk	Discuss alternative contraception with a doctor; use a backup method.
Rifampin, Rifabutin	Potent liver enzyme induction	Significantly reduces desogestrel levels, increasing pregnancy risk	Use a different contraceptive method or backup barrier contraception.
St. John's Wort	Liver enzyme induction	Decreases contraceptive efficacy, potential for breakthrough bleeding	Avoid this supplement entirely while on desogestrel.
Activated Charcoal	Decreased absorption	Prevents the proper absorption of the pill, reducing effectiveness	Avoid taking within several hours of your contraceptive pill.
Grapefruit Juice	Liver enzyme inhibition	Possible altered hormone levels; potential for increased side effects	Limit or avoid consumption; consult a healthcare provider.
HIV/HCV Medications (e.g., Efavirenz)	Enzyme induction/inhibition	Variable effect on desogestrel, potentially compromising efficacy	Counsel with a healthcare provider and consider a non-oral contraceptive method.
Colesevelam (Bile Acid Sequestrant)	Decreased absorption	Reduces absorption of desogestrel, compromising efficacy	Take desogestrel at least 4 hours before or after colesevelam.

Conclusion: Prioritizing Safety and Efficacy

For individuals relying on desogestrel for contraception, understanding and avoiding drug and supplement interactions is as important as taking the pill daily. The consequences of combining desogestrel with certain substances, particularly strong liver enzyme inducers and absorption inhibitors, can range from reduced contraceptive protection to an increased risk of adverse effects. Always inform your healthcare provider of all medications, supplements, and herbal remedies you are taking. This includes discussing any new prescriptions or over-the-counter products before starting them. In cases where an interacting medication is necessary, a backup or alternative form of contraception will be needed to ensure continued protection against pregnancy. Taking proactive steps and maintaining open communication with a healthcare professional can prevent complications and ensure safe and effective use of desogestrel.

Disclaimer: The information provided in this article is for informational purposes only and does not constitute medical advice. You should always consult with a qualified healthcare provider for any health concerns or before making any decisions related to your treatment or care.

Frequently Asked Questions

The main antibiotics to be cautious of are rifampin and rifabutin, which are strong enzyme inducers and can make desogestrel less effective. Most common antibiotics, however, do not cause this interaction.

Yes, St. John's wort is a known enzyme inducer that can speed up the breakdown of desogestrel in the liver. This can lead to reduced contraceptive effectiveness and is a severe interaction.

Grapefruit juice can affect how certain medications are metabolized. While the effect on desogestrel can be variable, some doctors recommend limiting or avoiding it, particularly when using a combined pill with ethinyl estradiol, to prevent potential side effects.

If you are less than 12 hours late taking a desogestrel pill, take it as soon as you remember. If you are more than 12 hours late, take the missed pill immediately and use a backup contraception method for the next two days.

No, not all seizure medications interact. Some enzyme-inducing anticonvulsants like carbamazepine, phenytoin, and phenobarbital do, but others, such as lamotrigine, gabapentin, and valproic acid, are considered less likely to interact significantly.

No, it is not recommended. Activated charcoal can bind to medications in the digestive system, preventing their absorption. It should not be taken within several hours of your desogestrel pill.

Some HIV medications, particularly certain protease inhibitors and non-nucleoside reverse transcriptase inhibitors (like efavirenz), can interact with desogestrel. Women with HIV should consult their healthcare provider to determine the best contraceptive approach.