Sexual Health Birth Control Using the Pill Print Types of Combination Birth Control Pills Differences Between Monophasic, Biphasic, and Triphasic Pills By Dawn Stacey, PhD, LMHC Updated May 20, 2019 More in Birth Control Using the Pill How to Choose Contraception Over-the-Counter Types of IUDs Hormonal Methods Permanent Methods Prescription Options Emergency Contraception Condoms When Birth Control Fails Talking About Birth Control View All Combination birth control pills are oral contraceptives that combine ethinyl estradiol and progestin. Even though all combination birth control pills have estrogen, they can differ in how much estrogen they contain. Combination birth control pills are also different from one another due to the amount and type of progestin that is in each pill brand. The combination of the amount of estrogen and the type and amount of progestin found in combination birth control pills can also cause different progestational, estrogenic, and androgenic effects. There is no "best" birth control pill brand. No birth control pill brand or pill type outranks all the others. Some pill brands may help to lower certain side effects. But all combination birth control pills are equally effective in preventing pregnancy—as long as the pills are used consistently and correctly. Multiphasic vs. Monophasic Birth Control Pills Envision/Getty Images Combination birth control pills are categorized as monophasic, biphasic, or triphasic depending on whether the level of hormones stays the same during the first three weeks of your menstrual cycle or if it changes. Keep in mind that for 28-day pill packs, the pills for the fourth week are usually placebo pills (and do not have any hormones). Multiphasic birth control pills were developed in the 1980s. Phasic birth control pills have differing amounts of hormones—designed to be taken at specific times throughout the course of each pill pack. These pills were originally developed to help lessen the side effects of monophasic birth control pills. When compared to monophasic combination pills, some multiphasic birth control pills may lower the total hormone dosage you may receive in each pill pack. They are also designed to more naturally mimic your body's menstrual cycle. Monophasic Birth Control Pills Carol Yepes/Getty Images Monophasic birth control pills have the same amount of estrogen and progestin in each active pill in the pill pack. The hormone levels in each pill stay consistent, so monophasic birth control pills may be less likely to cause side effects that could result from fluctuating hormones. Monophasic birth control pills are classified by their estrogen level: Low dose pills have the least amount of estrogen—usually 20 micrograms. But there is the birth control pill brand Lo Loestrin Fe. This is the only birth control pill that contains just 10 micrograms of estrogen, so it is quietly becoming very popular.Regular dose pills contain 30 to 35 micrograms estrogen.High-dose pills have about 50 micrograms of estrogen. Monophasic birth control pills work just as well as multiphasic pills. Low estrogen, monophasic pills may cause less bloating or breast tenderness but they may result in more spotting. Most women find that a monophasic birth control pill brand tends to be a good first choice. Biphasic Birth Control Pills Photo © Dawn Stacey Biphasic birth control pills change the level of hormones one time during the pill pack. Biphasic birth control pills deliver the same amount of estrogen each day, but the level of progestin is increased about halfway through the pill cycle. During the first half of the cycle, the progestin/estrogen ratio is usually lower. During the second half of the cycle, the progestin/estrogen ratio tends to be higher. The first seven to 10 days are of one strength (and usually one color), and the next 11 to 14 pills are of another strength (and another color). The last seven days (if included) are placebo pills and do not contain hormones. Triphasic Birth Control Pills Anne Rippy/Getty Images Triphasic birth control pills (like Ortho Tri-Cyclen) contain three different doses of hormones so the hormone combination changes approximately every seven days throughout the pill pack. Depending on the pill brand, the amount of estrogen may change as well as the amount of progestin. In a single month's supply, triphasic birth control pills may have a slow increase in estrogen, and some pills may also increase the dose of progestin. In each pill pack, the first few pills are one strength (and one color). The next phase of pills is another strength (and another color). The final phase of pills also change strength and are a different color. The last seven pills (if included) are placebo pills, so they do not contain hormones. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Email Address Sign Up There was an error. Please try again. Thank you, , for signing up. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Christin-Maitre S. History of oral contraceptive drugs and their use worldwide. Best practice & research. Clinical Endocrinology & Metabolism. 2013 Feb 28; 27(1):3-12.