How can a female of reproductive age with irregular menstrual cycles or amenorrhea induce a period?

How to Induce a Period in Women with Irregular Cycles or Amenorrhea

The approach to inducing a period depends entirely on the underlying cause—pregnancy must be ruled out first, then hormonal treatment with progestogen withdrawal or combined oral contraceptives can induce bleeding if the woman has adequate estrogen levels, but addressing the root cause (such as restoring energy balance in functional hypothalamic amenorrhea or treating thyroid dysfunction) is essential for long-term menstrual health. 1

Initial Diagnostic Steps

Before attempting to induce a period, critical evaluation is mandatory:

• Pregnancy test is the absolute first step in any woman with amenorrhea or irregular cycles 1, 2
• Initial laboratory workup should include: FSH, LH, prolactin, and TSH levels to identify the underlying cause 1, 3
• Pelvic ultrasound is recommended to evaluate for polycystic ovarian morphology, uterine abnormalities, or outflow tract obstruction 1, 4

Methods to Induce Menstrual Bleeding Based on Etiology

For Women with Adequate Estrogen (Normogonadotropic Amenorrhea)

Progestogen withdrawal test is the most straightforward approach when estrogen levels are adequate:

• Cyclic progestogen administration (such as micronized progesterone 200 mg for 12 days per month) will induce withdrawal bleeding in women who are not hypoestrogenic 1, 5
• Women who bleed in response to progestogen withdrawal have some ovarian activity and adequate estrogen 5
• Combined oral contraceptives can also induce regular withdrawal bleeding and are particularly useful if contraception is desired or if signs of hyperandrogenism (acne, hirsutism) are present 5, 4

For Women with Low Estrogen (Hypogonadotropic Amenorrhea/Functional Hypothalamic Amenorrhea)

Address the underlying cause first—this is critical:

• Increase caloric intake to achieve >30 kcal/kg fat-free mass/day as primary therapy 1
• Reduce excessive exercise volume and intensity if >10 hours/week of intense training 1
• Weight restoration to BMI ≥18.5 kg/m² is essential before considering hormonal interventions 1
• Recovery may take >6 months despite addressing energy deficits, so patience is required 1

If amenorrhea persists >6 months despite lifestyle modifications:

• Transdermal estradiol (100 μg patch twice weekly) with cyclic micronized progesterone (200 mg for 12 days/month) is preferred over oral contraceptives for bone health 1
• This regimen will induce withdrawal bleeding while protecting bone mineral density 1
• Oral contraceptives do NOT correct the underlying cause and provide false reassurance—they mask the problem without addressing energy deficit 1

For Specific Underlying Conditions

Hyperprolactinemia:

• Prolactin-lowering drugs (such as cabergoline or bromocriptine) will restore menstrual cycles 5
• Cyclic progestogen can be used for cycle disturbance while treating the underlying hyperprolactinemia 5

Thyroid dysfunction:

• Treat the thyroid disorder appropriately—menstrual cycles will normalize with thyroid hormone normalization 4

Polycystic Ovary Syndrome (PCOS):

• Cyclic progestogen (10-14 days per month) induces withdrawal bleeding and prevents endometrial hyperplasia 5
• Combined oral contraceptives are particularly effective for women with PCOS who also have acne or hirsutism 5

Critical Warnings and Pitfalls

Do not assume amenorrhea is benign:

• Even in athletes or stressed individuals, other pathology must be excluded 1
• DXA scan for bone mineral density is indicated if amenorrhea extends beyond 6 months, regardless of age 1, 6
• Prolonged hypoestrogenic states significantly increase osteoporosis risk, and 90% of peak bone mass is attained by age 18 1

Do not prescribe oral contraceptives as first-line for functional hypothalamic amenorrhea:

• This masks the problem without addressing the underlying energy deficit 1
• Oral contraceptives do not protect bone mineral density as effectively as physiologic estrogen replacement 1

Do not overlook eating disorders:

• Adolescents frequently minimize or deny disordered eating behaviors—direct questioning about specific behaviors is necessary 1
• Significant weight loss or signs of eating disorder require urgent evaluation by a multidisciplinary eating disorder team 1

When Hormonal Treatment is Inappropriate

Amenorrhea does not always require treatment to induce bleeding:

• If amenorrhea is due to contraceptive implant use, it is generally not harmful and requires only reassurance 7
• Amenorrhea in the context of contraceptive use does not require medical treatment—provide reassurance that this is not harmful 7

Referral Indications

Refer to endocrinology or gynecology if:

• Persistently abnormal hormone levels despite treatment 1
• Signs of pituitary pathology (headaches, visual changes, galactorrhea) 1
• Complex endocrine abnormalities identified on workup 4
• Infertility is a concern (inability to conceive after 12 months of unprotected intercourse) 4
• Primary care provider is not experienced with functional hypothalamic amenorrhea treatment 1