Drospirenone (Slynd): what it treats, how to take it, side effects
Last updated September 3, 2026.
Drospirenone (brand name Slynd) is a progestin-only birth control pill, taken every day with no estrogen in it. Each pack has 24 white active tablets (4 mg each) and 4 green inactive tablets, and unlike older progestin-only pills, it has a more forgiving 24-hour window for a late dose.
What does it treat?
It prevents pregnancy. Because it contains no estrogen, it is an option for people advised to avoid estrogen, including many who are breastfeeding, over 35 and smoking, or who get migraines with aura, though the final call belongs with the prescriber. It works mainly by thickening cervical mucus and suppressing ovulation.
How do you take it?
Take one tablet by mouth once a day at the same time every day, with no breaks between packs: 24 white tablets, then the 4 green inert tablets, then straight into the next pack. The first pack starts on day 1 of your period. If you miss a white tablet by more than 24 hours, take it as soon as you remember, keep the rest on schedule, and use backup contraception for the next 7 days; the pack insert has the full missed-pill chart. Missed green tablets can simply be skipped. St. John's wort, potassium supplements, and regular NSAID use all interact with drospirenone, so report everything you take.
Side effects to know
- Common: irregular bleeding or spotting, acne, headache, breast pain or tenderness, nausea, weight gain, painful periods, and lower libido; each appeared in more than 1% of users in trials. Periods may become irregular or stop, which on this pill is expected, not dangerous.
- Serious: high potassium (muscle weakness, slow or irregular heartbeat), blood clots, mood changes including depression, and the rare ectopic pregnancy.
Who should not take it?
Do not use drospirenone if you have kidney, liver, or adrenal disease (high potassium risk), a history of blood clots or certain clotting disorders, or unexplained vaginal bleeding. Tell your prescriber about depression, diabetes, and any medicines that raise potassium, such as some blood pressure drugs and daily NSAIDs. If pregnancy is confirmed, stop the pill.
When is it an emergency?
Call 911 for possible clot signs: sudden chest pain, coughing blood, one-sided leg swelling with pain, sudden severe headache, or vision loss. Severe abdominal pain with a missed period and spotting can signal an ectopic pregnancy and needs same-day care. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
How is Slynd different from the old mini-pill?
Older progestin-only pills like norethindrone demand same-time dosing within about 3 hours and often do not stop ovulation. Drospirenone 4 mg suppresses ovulation more reliably and allows a 24-hour late window before protection is considered compromised, with a 7-day backup rule after a missed active pill.
Will drospirenone stop my period?
It can, and that is normal on this pill. Irregular bleeding and spotting are the most common effects in the first months, and some users stop bleeding entirely. Amenorrhea on a progestin-only pill is expected; a missed period with pregnancy symptoms still warrants a test.
Does drospirenone raise potassium?
It can. Drospirenone is chemically related to the diuretic spironolactone, and the label carries a hyperkalemia warning. People with kidney, liver, or adrenal disease should not take it, and potassium supplements, daily NSAIDs, and certain blood pressure medicines raise the risk.
Is drospirenone safe while breastfeeding?
Progestin-only pills are the usual hormonal choice during breastfeeding because they lack estrogen, which can affect milk supply. Small amounts of hormone do pass into milk. Your prescriber weighs your specific situation, but this class is the standard estrogen-free option for nursing parents.
Does the drospirenone pill cause weight gain?
Weight increase was reported in more than 1% of users in trials, though individual experience varies widely and controlled studies generally find small average changes. If the scale moves after starting, bring it to your prescriber rather than stopping mid-pack without a plan.
What if I miss a pill?
For a white active tablet taken more than 24 hours late: take it as soon as you remember (even if that means two in one day), continue the pack, and use backup contraception for 7 days. The more pills missed, the higher the pregnancy risk. Green inactive tablets can be skipped entirely.