How They Work
 
These pills work mainly by changing the thickness of the cervical mucous so that sperm have a harder time reaching the egg.  They can also prevent pregnancy by changing  the lining of the uterus so that a fertilized egg cannot implant.
 
 
When Are They Effective?
 
Progestin pills are not completely effective for the first month.  Therefore, you should abstain from sexual intercourse or use a backup method of birth control during your first cycle.
 
 
Advantages
 
In addition to the advantages listed above, the progestin pill:

• Does not contain estrogen.
• Is great for people that cannot take estrogen and still want the benefits of the birth control pill.

 
 
Disadvantages
 
In addition to the disadvantages listed above:

• Many women taking the progestin-only pill experience irregular vaginal bleeding, which is normal on this type of pill.  Some women experience light periods.  Others don’t have periods for several months.
• Since the progestin-only pill is very time sensitive it must be taken at the same time every day for maximum effectiveness.

 
 
What To Do If You’ve Missed a Pill
 
If you’ve missed one pill then you should…
Take the pill as soon as you remember that you have forgotten it and take the next pill at the usual time.  It is important that you use a backup method of birth control for the rest of the MONTH!!!
If you are more than three hours late taking a pill you should abstain from intercourse or use another method of birth control for the next two days.
This is a good time to ask your partner to use both condoms and the withdrawal method, which reduces the risk of pregnancy and the transmission of STD’s.
Two or more pills:
Take 2 pills as soon as you remember for two days.  It is also essential that you abstain from sex or use another method of birth control for the rest of the month!!
 
 
Effectiveness
 
Progestin-only pills have a slightly higher failure rate than the combination pill.  Among perfect users the failure rate is .5% of women, and among typical users the failure rate is 5%.
 
 
This Pill Might Be Right For You If…
 

• You cannot take estrogen for medical reasons.
• You have high blood pressure.
• You have recently had a baby.
• You have sickle cell disease.

 
 
See Your Doctor Right Away If…
 

• You have missed a period after months of regular cycles.
• You are experiencing abdominal pain.
• You are having severe headaches.

 
 
Created April 6, 2003, last updated May 31, 2007