Supplements and birth control pills: St. John's wort, folate and potassium

October 24, 2026By VitOptics Staff

Short answer: The one supplement every birth control pill source in this guide names is St. John's wort. The labels say it may make the pill less effective or cause breakthrough bleeding, and MedlinePlus asks you not to start it while taking the pill without discussing it with your healthcare provider. Beyond that, the questions depend on your exact pill: Beyaz and Safyral already contain a folate, some packs, such as Lo Loestrin Fe, include tablets with iron, and pills with drospirenone (such as Yaz, Yasmin and Slynd) may raise potassium, so potassium supplements matter. None of these labels sets a separation time for vitamins or minerals. Do not stop or change your birth control without talking to your doctor or pharmacist.

Birth control pills come in two main types. MedlinePlus explains that combination pills contain an estrogen and a progestin and work mainly by preventing ovulation (the release of eggs from the ovaries). Progestin-only pills prevent ovulation and also change the cervical mucus and the lining of the uterus. For anyone adding a supplement, three things matter: the exact pill you take, the one herb on every list, and what is already in your pill pack.

Check the exact pill you take

MedlinePlus says oral contraceptives come in many brands with different doses, and that some packs "may also contain inactive tablets or ones containing iron." The name on your pack tells you which kind you have:

Combination pills. Ethinyl estradiol (an estrogen) with a progestin such as norethindrone (for example Junel, Loestrin or Blisovi), levonorgestrel (for example Aviane, Levora or Seasonique) or drospirenone (for example Yaz, Yasmin, Loryna or Syeda).
Progestin-only pills. Norethindrone (for example Camila, Errin or Heather), norgestrel (Opill, sold without a prescription) and drospirenone (Slynd).
Pills with a vitamin or mineral built in. Beyaz and Safyral add a folate to every tablet, and some packs, such as Lo Loestrin Fe, include tablets that contain iron.

MedlinePlus asks you to take your pill at the same time every day. The labels' timing rules are about the pill itself; none of them sets a gap between the pill and a vitamin or mineral. So the questions below are about what is in your products, not about the clock.

St. John's wort: on every list

Each MedlinePlus page linked above lists St. John's wort as a nonprescription or herbal product that may interact with the pill, and asks you not to start it while taking the pill without discussing it with your healthcare provider. The labels explain why. The Yaz prescribing information says drugs or herbal products that induce certain enzymes, including CYP3A4, "may decrease the effectiveness of COCs or increase breakthrough bleeding" (COCs are combination oral contraceptives), and names "products containing St. John's wort" among them. The Camila label, for a progestin-only pill, says herbal products containing St. John's wort may reduce the effectiveness of contraceptive steroids and may cause breakthrough bleeding, and the Slynd label lists it too.

The Yaz label also tells prescribers to counsel women "to use an alternative method of contraception or a back-up method when enzyme inducers are used with COCs, and to continue back-up contraception for 28 days after discontinuing the enzyme inducer." The Opill Drug Facts label asks you to talk to a doctor or pharmacist before use if "you are taking a supplement containing St John’s Wort (an herbal ingredient)."

NIH's National Center for Complementary and Integrative Health (NCCIH) names birth control pills among the "crucially important medicines" whose effects St. John's wort can weaken. On a label it may also appear as hypericum or by its Latin name, Hypericum perforatum. NCCIH says it is most widely promoted for symptoms of depression and also for menopause symptoms, so read the full ingredient list of any blend sold for mood. If you already take it, tell your prescriber or pharmacist before you start or change anything.

Estrogen used for menopause carries its own labels, and they name St. John's wort too; our guide to estradiol and supplements covers them.

Does the pill lower your vitamin levels?

You'll see claims that birth control pills "deplete" vitamins. None of the labels or MedlinePlus pages cited in this guide says the pill lowers any vitamin or mineral. The fact sheets for health professionals from NIH's Office of Dietary Supplements (ODS) on vitamin B6, vitamin B12 and folate don't list birth control pills among their examples of medicines that affect those vitamins.

That isn't proof of no effect. It means these sources give no reason to add a supplement because of the pill alone. If you have another reason to think a level is low, such as a restricted diet, ask your doctor about a blood test rather than guessing. Our guide on why tests come first explains the idea.

Folate is already in Beyaz and Safyral

The Beyaz and Safyral labels describe pills that are also meant to raise folate levels in women who choose an oral contraceptive. Every tablet in these packs contains 0.451 mg of levomefolate calcium, a form of folate, including the last tablets in each pack, which contain no hormones. Folic acid, the form in many supplements, is a B-complex vitamin.

Both labels tell prescribers to "consider other folate supplementation that a woman may be taking" before prescribing, and both note that "folates may mask vitamin B12 deficiency." If your pill is one of these, count it when you look at the folate or folic acid line in a multivitamin, prenatal vitamin or B-complex, and bring both labels to your pharmacist. Our guide on how to check for duplicate supplement ingredients shows how to line them up. The labels also say folate supplementation should be kept up if a woman stops the pill because she becomes pregnant, so if that happens, ask your doctor what to take.

Iron in some pill packs

In some packs, the last tablets contain iron instead of being inactive. In Lo Loestrin Fe, for example, the 2 brown tablets each contain 75 mg of ferrous fumarate, and the label says: "The ferrous fumarate tablets do not serve any therapeutic purpose." They are still iron, so count them if you take an iron supplement or a multivitamin with iron, and mention them if another medicine you take has iron timing rules, such as levothyroxine or some antibiotics.

Drospirenone pills and potassium

Drospirenone, the progestin in Yaz, Yasmin, Beyaz, Safyral and Slynd, may increase potassium. The Yaz label says its 3 mg of drospirenone has the potential to cause hyperkalemia (a high blood potassium level) in high-risk patients, "comparable to a 25 mg dose of spironolactone." It says women on daily, long-term treatment for chronic conditions with medicines that may increase potassium should have their potassium checked during the first treatment cycle, and it lists "potassium supplementation" among those medicines, alongside ACE inhibitors, angiotensin-II receptor antagonists, potassium-sparing diuretics, heparin, aldosterone antagonists and NSAIDs.

The Slynd label says potassium should be checked before starting and during the first treatment cycle in the same situation, and the MedlinePlus page for drospirenone-only pills lists potassium supplements among the products that may interact. Potassium can also be one line in a multivitamin or mineral formula. If you take a drospirenone pill, check every Supplement Facts panel for potassium, and ask your prescriber whether a potassium check makes sense for you. Our guide to lisinopril, losartan and potassium shows where potassium shows up on labels, and if you take one of those medicines too, both labels point the same way. If you also take spironolactone, our guide to spironolactone and potassium covers its labels.

Vitamin C, grapefruit and thyroid medicine

The Yaz label's list of substances that can raise hormone levels includes this line: "Ascorbic acid and acetaminophen may increase plasma EE concentrations, possibly by inhibition of conjugation." Ascorbic acid is vitamin C, and EE is ethinyl estradiol, the estrogen in combination pills. The Lo Loestrin Fe label has similar wording. Neither label gives an instruction to avoid or space vitamin C, but if you take a high-dose vitamin C product, mention it at your next refill.

The Yaz label also names grapefruit juice among the CYP3A4 inhibitors that "can increase the plasma concentrations of the estrogen or the progestin or both." MedlinePlus's diet advice for these pills is to continue your normal diet unless your doctor tells you otherwise, so if grapefruit is a regular part of yours, ask your pharmacist.

One more label note matters if you take thyroid medicine: "Women on thyroid hormone replacement therapy may need increased doses of thyroid hormone because serum concentration of thyroid-binding globulin increases with use of COCs." If you take levothyroxine, see our levothyroxine timing guide, and ask your prescriber whether your thyroid levels should be checked when you start or change the pill.

Vomiting, diarrhea and a new supplement

The directions for every pill in this guide cover vomiting and diarrhea, because they can keep the pill from being fully absorbed. MedlinePlus says vomiting or diarrhea may make a combination pill not work as well, and that you may be told to use a backup method for 7 days. The Opill label says that if you vomit or have severe diarrhea within 4 hours of taking a tablet, use a condom or another barrier method every time you have sex for the next 2 days (48 hours). Your own pill's leaflet has the exact rule.

That matters when you start something new, because some supplements can upset the stomach at high doses. ODS says high doses of magnesium from supplements or medicines often cause diarrhea, and that high doses of vitamin C can lead to diarrhea and other stomach upset. If a new product gives you diarrhea or makes you vomit, follow your pill's directions for that situation and ask your pharmacist about the product.

Herbs sold for periods or hormones

None of the labels or MedlinePlus pages cited here names chasteberry (vitex), black cohosh or other herbs sold for periods or "hormone balance." That isn't a clearance. NCCIH's general advice applies: if you take any type of medicine, talk with your health care provider before using herbal products, because some herbs and medicines interact in harmful ways. Read the full ingredient list of any blend, since St. John's wort can turn up in products sold for mood or menopause.

What to ask at your next refill

Is my pill a combination pill or a progestin-only pill, and does it contain drospirenone, a folate or iron?
Here are the labels of everything I take. Does any of them contain St. John's wort, hypericum or another ingredient that could make my pill less effective?
If my pill contains drospirenone, should my potassium be checked, given my supplements and other medicines?
If my pill contains folate, how much folate am I getting in total?
If a supplement upsets my stomach, what does my pill's leaflet say to do?

MedlinePlus suggests keeping a written list of all of the prescription and nonprescription medicines, vitamins, minerals and dietary supplements you take, and bringing it each time you visit a doctor.

Where VitOptics fits

VitOptics builds personalized daily supplement packs from a free, three-minute assessment. The assessment asks for your prescription medicines by name, whether you are pregnant, breastfeeding or trying to conceive, your conditions and the supplements you already take, so your birth control pill is part of the check from the start. Give the exact brand name. Automated checks review the recommendation; some profiles need additional review by a person on our team. A second automated check reads the whole pack before release.

Your result lists every formula, the amount of each ingredient and the reason it is there, including any folate, iron or potassium in a multivitamin, B-complex or mineral formula, and it names one time of day for the whole pouch. Compare it with your pill's label and show it to your doctor or pharmacist before you start.

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Sources

This article is for educational purposes and is not medical advice. Supplements are not intended to diagnose, treat, cure or prevent any disease.

Prepared with AI assistance using the sources linked in this article.

Last updated: October 24, 2026

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