What Is Rivelsa 91 Day? Uses, Dosage, and What You Need to Know in 2026

Rivelsa 91 Day is a prescription oral contraceptive approved by the FDA to prevent pregnancy. Unlike standard birth control pills taken in 28-day cycles, Rivelsa uses a 91-day (13-week) cycle—giving you approximately 4 periods per year instead of 13. Here's everything you need to know about what it is, what's in it, how to take it, and who it's for.

What Is Rivelsa 91 Day?

Rivelsa 91 Day is a combination oral contraceptive (COC) containing two hormones: levonorgestrel (a progestin) and ethinyl estradiol (a synthetic estrogen). It is the FDA-authorized generic version of Quartette, manufactured by Teva Pharmaceuticals USA. Unlike standard 28-day pills, Rivelsa is taken for 91 consecutive days with only 4 scheduled periods per year.

What makes Rivelsa unique among extended-cycle pills is its quadriphasic design—the estrogen dose steps up gradually over the 91-day cycle while the progestin stays constant. This graduated approach was designed to reduce the unscheduled breakthrough bleeding that is common with older monophasic extended-cycle pills.

What Is in Each Rivelsa 91 Day Pack?

Each Rivelsa 91 Day pack contains 91 tablets in four phases:

42 light pink tablets: 0.15 mg levonorgestrel + 0.02 mg ethinyl estradiol (days 1-42)

21 pink tablets: 0.15 mg levonorgestrel + 0.025 mg ethinyl estradiol (days 43-63)

21 purple tablets: 0.15 mg levonorgestrel + 0.03 mg ethinyl estradiol (days 64-84)

7 yellow tablets: 0.01 mg ethinyl estradiol only, no progestin (days 85-91 — this is when your scheduled period occurs)

Important: Do not skip the yellow tablets. Unlike placebo pills in some 28-day packs, the yellow tablets contain active medication (low-dose estrogen) and should be taken as directed.

What Is Rivelsa 91 Day Used For?

Rivelsa is FDA-approved for one indication: prevention of pregnancy in females of reproductive potential. However, prescribers also use it off-label for:

Menstrual suppression (reducing period frequency and severity)

Endometriosis-related pain management

Dysmenorrhea (painful periods)

Menstrual migraine prevention (reducing hormonal trigger cycles)

Iron-deficiency anemia related to heavy menstrual bleeding

PCOS cycle regulation and androgen suppression

How Do You Take Rivelsa 91 Day?

Take one tablet daily by mouth at the same time every day for 91 days in the order directed on the blister pack. Taking it at the same time each day maximizes effectiveness. Begin your first pack on the first Sunday after your period starts (if your period starts on a Sunday, begin that day). Use backup contraception (condoms) for the first 7 days of your first pack.

After finishing one 91-day pack, start the next pack immediately on the following day (the same day of the week you started the first pack). Do not take a break between packs.

Who Should NOT Take Rivelsa 91 Day?

Rivelsa 91 Day is contraindicated in patients who:

Are over 35 years old AND smoke cigarettes (boxed warning)

Have a history of or high risk for blood clots (DVT, PE, stroke, or heart attack)

Have uncontrolled high blood pressure

Have migraines with aura

Are pregnant or think they may be pregnant

Have had or currently have breast cancer or other hormone-sensitive cancers

Have significant liver disease or liver tumors

Ready to Fill Your Rivelsa Prescription?

If you have a prescription and need to find Rivelsa in stock near you, medfinder calls pharmacies in your area on your behalf and texts you the results. Want to learn more about how it works? See our guide on how Rivelsa 91 Day works.