What Is Tri-Lo-Mili? Uses, Dosage, and What You Need to Know in 2026

Tri-Lo-Mili is a prescription birth control pill used by women to prevent pregnancy. It's a generic oral contraceptive manufactured by Aurobindo Pharma and is one of several generic equivalents of the discontinued brand-name Ortho Tri-Cyclen Lo. Here's everything you need to know about Tri-Lo-Mili in 2026 — from how it works to how to take it correctly.

What Is Tri-Lo-Mili?

Tri-Lo-Mili (norgestimate and ethinyl estradiol) is a triphasic combination oral contraceptive pill (COC). It contains two types of female hormones — norgestimate (a synthetic progestin) and ethinyl estradiol (a synthetic estrogen). It is classified as a "low-dose" pill because the estrogen level (0.025 mg ethinyl estradiol) is lower than many other combination pills.

"Triphasic" means the pill uses three different hormone doses over the course of one cycle — mimicking the natural hormonal fluctuations of the menstrual cycle more closely than single-dose (monophasic) pills. The progestin dose gradually increases week by week while the estrogen remains constant.

What Is Tri-Lo-Mili Used For?

Tri-Lo-Mili is FDA-approved for one indication: preventing pregnancy (contraception). It is prescribed to females of reproductive potential who want hormonal birth control.

As a secondary benefit — though not an official FDA-approved indication for the Tri-Lo-Mili formulation specifically — patients often report improvements in:

Menstrual cycle regularity

Reduced menstrual blood loss and cramps

Reduced ovarian cyst formation

Note: The higher-estrogen version of this drug class — Tri-Mili (norgestimate/EE 0.035 mg) — is specifically FDA-approved for treating acne in women 15 and older. Tri-Lo-Mili (0.025 mg EE) does not carry this indication.

How Effective Is Tri-Lo-Mili?

With perfect use (taking the pill at the same time every day without missing any doses), combination oral contraceptives including Tri-Lo-Mili are over 99% effective at preventing pregnancy. With typical use (accounting for occasional missed pills), effectiveness is approximately 91-93%, meaning about 7-9 out of 100 women may become pregnant in a year.

The clinical study for Tri-Lo-Mili found approximately 3 out of 100 women may become pregnant in the first year of use, based on study conditions. Consistent daily use is the single most important factor in effectiveness.

Tri-Lo-Mili Dosage and Pill Schedule

Tri-Lo-Mili comes in a 28-tablet blister pack with the following schedule:

Days 1-7 (Week 1): 7 white to off-white tablets — norgestimate 0.180 mg + ethinyl estradiol 0.025 mg

Days 8-14 (Week 2): 7 pale blue to bluish-white tablets — norgestimate 0.215 mg + ethinyl estradiol 0.025 mg

Days 15-21 (Week 3): 7 blue to light blue tablets — norgestimate 0.250 mg + ethinyl estradiol 0.025 mg

Days 22-28 (Week 4): 7 green reminder tablets — no active hormones (placebo); take to maintain the daily habit while withdrawal bleeding occurs

You must take the tablets in the correct order (follow the arrows on the blister pack). Taking them out of order could reduce effectiveness.

How to Start Tri-Lo-Mili

There are two common starting options, which you should decide with your healthcare provider:

Day 1 Start: Begin on the first day of your period. No backup contraception needed.

Sunday Start: Begin on the first Sunday after your period starts (or on the Sunday if your period starts on Sunday). Use backup contraception for the first 7 days.

Who Should NOT Take Tri-Lo-Mili?

Tri-Lo-Mili is contraindicated (should not be used) in women who:

Are over 35 years old and smoke cigarettes (Black Box Warning)

Have a history of blood clots, stroke, heart attack, or certain heart conditions

Have hormone-sensitive cancers (breast, uterine, cervical)

Have uncontrolled high blood pressure or undiagnosed vaginal bleeding

Are pregnant or breastfeeding (may reduce milk supply)

Take the Hepatitis C drug combination ombitasvir/paritaprevir/ritonavir

To learn more, see our guides on how Tri-Lo-Mili works and Tri-Lo-Mili side effects.