What Is Kelnor 1/35 28 Day? Uses, Dosage, and What You Need to Know in 2026

Kelnor 1/35 28 Day is a combination oral contraceptive ("the pill") manufactured by Teva Pharmaceuticals. It contains two synthetic female hormones: ethynodiol diacetate (a progestin) and ethinyl estradiol (an estrogen). Together, these hormones work to prevent pregnancy. Here is everything you need to know before starting or continuing this medication.

What Is Kelnor 1/35? The Basics

Kelnor 1/35 is a generic oral contraceptive that was originally developed as a substitute for the discontinued brand Demulen 1/35. The "1/35" in its name refers to the active hormone dosages per tablet: 1 mg of ethynodiol diacetate and 35 mcg (micrograms) of ethinyl estradiol.

The 28-day regimen contains 28 tablets arranged in a blister pack: 21 active (light yellow) tablets containing the hormones, followed by 7 white placebo tablets containing no active ingredients. The placebo week allows for a withdrawal bleed (your "period" while on the pill).

What Is Kelnor 1/35 Used For?

The FDA-approved indication for Kelnor 1/35 is the prevention of pregnancy in women who choose to use oral contraceptives. When taken correctly and consistently, it is approximately 99% effective at preventing pregnancy with perfect use and about 91% effective with typical use.

While not FDA-approved for these purposes, many patients and providers also note benefits including:

More regular, lighter, and less painful menstrual periods

Reduced risk of ovarian cysts

Reduced risk of iron-deficiency anemia from heavy periods

How Do You Take Kelnor 1/35?

Take one tablet daily, at the same time each day, with or without food. Taking it at the same time every day is important — it maximizes effectiveness and reduces the risk of breakthrough bleeding.

Day 1 Start: Begin taking the light yellow active tablets on the first day of your menstrual period. Contraceptive protection begins immediately.

Sunday Start: Begin on the first Sunday after your period starts. Use a backup method (condoms) for the first 7 days if you use a Sunday start.

After the 21st active tablet, take one white placebo tablet daily for 7 days. Your period (withdrawal bleed) will typically occur during this week. Begin the next pack on day 29, regardless of whether your period has ended.

What If I Miss a Pill?

Missing pills can reduce effectiveness and increase the risk of breakthrough bleeding. Here are the general guidelines:

Missed 1 active pill: Take it as soon as you remember. You can take two pills on the same day if needed. No backup contraception required.

Missed 2 or more active pills: Take 2 pills per day for 2 days to catch up, then continue your regular schedule. Use backup contraception for at least 7 days.

Missed placebo pills: No action needed — just resume your schedule. Missing placebo pills does not increase your risk of pregnancy.

Who Makes Kelnor 1/35?

Kelnor 1/35 is manufactured by Teva Pharmaceuticals USA. It is a generic version of the discontinued brand Demulen 1/35. The product is also available under the brand names Zovia 1/35E and Valtya 1/35, which contain the identical active ingredients.

Important Things Kelnor 1/35 Does NOT Do

It does not protect against HIV, AIDS, or other sexually transmitted infections (STIs)

It does not terminate an existing pregnancy

It does not function as emergency contraception when used after unprotected sex

Finding Kelnor 1/35 at a Pharmacy

Because Kelnor 1/35 is a niche generic, it's not consistently stocked at every pharmacy. If you're having trouble locating it, medfinder can help by calling pharmacies near you to check which ones have it in stock.

Curious about how Kelnor 1/35 actually works in your body? Read: How Does Kelnor 1/35 Work? Mechanism of action explained in plain English.