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Standard Days Method

SDM is a simple, modern, fertility awareness-based method of family planning that was developed and tested by IRH in 2001. Based on reproductive physiology, SDM identifies a fixed set of days in each menstrual cycle when a woman can get pregnant if she has unprotected intercourse. If the woman does not want to get pregnant, she and her partner avoid unprotected intercourse on days 8 through 19 of her cycle.

A woman can use CycleBeads®, a color-coded string of beads, to help track the days of her menstrual cycle and see which days she is most likely to get pregnant. She also can use the CycleBeads® app on her smartphone, or CycleBeads Online through any internet connected device. CycleTel™ is an SMS (text messaging) service currently being tested in India.

Given its ease of use and lack of side effects, SDM appeals to many couples who are not currently using any method and those who are concerned about the side effects or health complications of hormonal methods. It also empowers women by helping them learn about their bodies and fertility. This family planning method is an important addition to the method mix that brings new users to family planning and helps many couples prevent unplanned pregnancy.

SDM is incorporated in the national family planning norms and policies in many countries around the world. WHO recognizes SDM as an evidence-based practice and includes it in their family planning global guidance documents. Contraceptive Technology, the family planning reference book for health professionals, also includes SDM.
Standard Days Method



In an efficacy study, SDM was found to be more than 95% effective. That means that out of 100 women using the method for one year, fewer than five of them would get pregnant if they used SDM correctly.

However, the study also found that women who do not keep careful track of their cycle days or have unprotected intercourse on days 8 through 19 of their cycles are much more likely to get pregnant. When pregnancies occurring with correct use and with incorrect use of the method were added together, the total was approximately 12 pregnancies for every 100 women/year of method use.

The effectiveness of SDM is similar to that of some other user-dependent methods of family planning.

How does SDM work (with CycleBeads)?

CycleBeads®, a color-coded string of beads, facilitates use of the Standard Days Method® (SDM) by helping women track their menstrual cycle and identify their fertile days. As described below, each bead represents a day of a woman’s menstrual cycle.

CycleBeads has a black rubber ring that the woman moves over one bead each day, in the direction of the arrow. When the woman starts her period, she puts the ring on the first bead, which is red. She continues moving the ring one bead each day of her cycle. When the ring is on a dark bead, she is on a day in her cycle when she can have intercourse without getting pregnant. When she is on a day represented by the white beads (days 8-19), she may be fertile and could get pregnant if she has unprotected intercourse. SDM works well for women who usually have menstrual cycles between 26 and 32 days long. Women who have cycles shorter than 26 days or longer than 32 days are not good candidates for this method. Also, women who would not be able to avoid unprotected intercourse on the days they might get pregnant are not likely to be successful using this method.

Where to get it


A woman can begin using SDM right away if she is eligible. To obtain CycleBeads, the CycleBeads® app, or CycleBeads Online, she can visit

Screen Yourself

Method materials are available in our Resource Library.

Evidence & Research

Efficacy Study

Interested in the evidence behind this method? See the collection of peer reviewed journal articles published about SDM here.

What are users saying?


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