• Advise that many women experience irregularities in menstruation while using a progestogen-only injectable:
• A few women have very heavy or prolonged bleeding. This can be managed by:
• Treating with a combined oral contraceptive (either cyclically or continuously) for up to 3 months.
• Treating with mefenamic acid 500 mg twice or three times a day for 5 days.
• Changing to another contraceptive method.
• Some women experience prolonged amenorrhoea; this is most likely in older women and, with forewarning, is usually accepted.
• Exclude or manage other situations which could result in unscheduled bleeding, such as:
• Sexually transmitted infections.
• Risk of STI if the woman is under 25 years, or has a new sexual partner, or more than one partner in the last year.
• Pregnancy.
• Gynaecological conditions such as cervical cancer. Provided there is consistent and correct use of contraception, speculum examination is warranted:
• For persistent bleeding beyond the first 3 months of use.
• For new symptoms or a change in bleeding after at least 3 months of use.
• If the woman has not participated in a National Cervical Screening programme.
• If requested by the woman.
• After a failed trial of modification of treatment.
• If there are other symptoms such as pain, dyspareunia, or post coital bleeding. (Note that these symptoms also warrant pelvic examination.)

In depth