The Billings or Cervical Mucus Method: What Is It and What are its Risks?

The Billings method has the advantage that it's completely natural and doesn't generate any side effects. On the other hand, it requires a great deal of discipline and perseverance for those who use it. Even so, it's not always effective.
The Billings or Cervical Mucus Method: What Is It and What are its Risks?
Leidy Mora Molina

Reviewed and approved by the nurse Leidy Mora Molina.

Written by Edith Sánchez

Last update: 31 October, 2022

The Billings method is a natural contraceptive technique. It’s used, like any contraceptive method, for birth control. The difference is that, in this case, no hormones or devices are used in the uterus.

This method is based on the observation and interpretation of the characteristics of the cervical mucus. Depending on these changes, a woman is able to identify when she’s in her fertile period and when she’s not. The Billings method is considered relatively effective.

It’s estimated that when the Billings method is applied perfectly, it’s 97% effective. Because it’s completely natural, it avoids the possible side effects that other methods of contraception sometimes cause.

What is the Billings method?

Billings method
Billings is a non-hormonal, non-barrier method of contraception.

The Billings method is a procedure that allows you to control conception. It’s also known as the “Billings ovulation method” or ” cervical mucus method.” It’s based on detailed observation of cervical mucus patterns throughout the menstrual cycle.

Cervical mucus changes in color, texture, and quantity during the menstrual cycle. This change is most noticeable on the days when ovulation occurs. This is because the body must create the right environment to facilitate pregnancy.

The key to the Billings method is learning to identify these changes in the cervical mucus. This comes out of the cervix through the vagina in the form of discharge. By recognizing the fertile days through this discharge, it’s possible to predict when there is a greater chance of pregnancy and when there’s not.

It’s common to use another contraceptive method, such as condoms, on fertile days. It’s also common for the Billings method to be combined with other techniques, such as basal temperature monitoring or an electronic fertility monitor. This ensures effectiveness.

Applying the Billings method

To apply the Billings method, the cervical mucus – i.e., vaginal discharge –   should be checked every day, and then the changes should be recorded on a chart. It’s best to start the day after the end of menstruation.

The following steps should be completed:

  • Clean the opening of the vagina. This can be done with toilet paper or tissue. It’s best to do this before urinating.
  • Observe the color and texture of the mucus.
  • Make the same observation, but this time by observing the underwear.
  • Introduce your fingers into your vagina and observe the mucus that remains impregnated. Your hands should be clean when you do this.
  • Rub and spread the discharge between your index finger and thumb. Note the consistency and color.
  • Note everything you’ve observed on your chart.

It’s best not to have sex or use a condom during the first menstrual cycle of observation. This is because sex can cause changes in the cervical mucus and leads to confusion.

Changes in cervical mucus and their interpretation

Throughout the menstrual cycle, several changes occur in the cervical mucus, and it’s very important to be aware of them in order to apply the Billings method correctly. The three observable variables are color, texture, and quantity.

The times in the menstrual cycle when changes occur are as follows:

  • The period. During menstruation, it’s not possible to observe the flow of cervical mucus. These days are considered infertile.
  • At the end of the period. This corresponds to the three or four days after the end of menstruation. The flow is very scarce, and therefore, these are considered “dry days.” These are also infertile days.
  • The days prior to ovulation. There’s a greater amount of mucus, and it’s yellow, white, or cloudy. This corresponds to the moment when the egg begins to mature. It lasts between three and five days. These are days of possible fertility.
  • During ovulation. This is the stage of the month with the greatest volume of cervical mucus. The texture is similar to egg white and can be stretched between the fingers. It lasts about four days and corresponds to the most fertile phase of the entire month.
  • After ovulation. The cervical mucus becomes noticeably thinner and becomes sticky and cloudy. Then, there’s no mucus or very little mucus. This period lasts between 11 and 14 days. These are infertile days. After that, the period occurs, and the cycle restarts.

We think you may be interested in reading this, too: Ovulatory Dysfunction: What Is it and How to Deal with It?

The risks of using this method

As we said at the beginning, the Billings method is only safe if applied correctly. However, formal training is usually required to achieve this. Also, consistency is a must, as it’s necessary to check your cervical mucus every day.

Some estimates indicate that out of every 100 women using the Billings method, 23 will become pregnant during the first year of regular use. Among women who use the method perfectly, the pregnancy rate is three per 100.

Although this method is natural and non-invasive, it does not protect against sexually transmitted diseases. Although it is cheaper than any other method, the Billings method is often less effective in preventing pregnancy.

Tips and recommendations

Billings method for sex
Applying the Billings method correctly requires knowledge and consistency.

There are several factors that can cause changes in cervical mucus. Sexual intercourse alone can cause changes in the flow, and this often leads to confusion. Other factors that alter these fluids include the following:

  • Using lubricants in the vagina
  • Certain medications
  • Douching
  • Breastfeeding
  • Recent use of hormonal contraceptives
  • Premature menopause
  • Sexually transmitted diseases
  • Vaginitis

The two-day method is an alternative to the Billings method. In this case, a woman only has to ask herself two questions:

  • Do I have cervical mucus today?
  • Did I have cervical mucus yesterday?

If the answer to both questions is “no,” it’s likely safe to have sex with no risk of pregnancy. In any case, it could not be said that the two-day method is more effective than the Billings method, but it does require less perseverance.

Like this article? You may also like to read: Cervical Mucus: 9 Facts Every Woman Should Know

Combine the Billings method with another method if you want to avoid pregnancy

The Billings method may be more useful for women who want to get pregnant than for those who want to avoid conception. In addition to the aforementioned weaknesses of this technique, it should be added that some women have poor flow throughout the month.

If a woman wants to use the Billings method, it’s best to consult with her healthcare provider for guidance. She may also need to combine it with other methods if her goal is to avoid pregnancy.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Curriá, M. I. (2010). LH y moco cervical en el reconocimiento de la fertilidad.
  • Catelo Ayala, L. La curva de temperatura basal en la esterilidad. Revista de la Facultad de Medicina, 3(3).
  • Padilha, T., & Deretti, E. A. (2021). Método de Ovulación Billings: entre la eficacia y el desconocimiento. Revista Bioética, 29, 208-219.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.