What regimen should I prescribe to taper Aygestin (norethindrone acetate)?

Aygestin (Norethindrone Acetate) Tapering Regimen

For patients discontinuing norethindrone acetate after therapeutic use, reduce the dose by 2.5 mg every 2 weeks until discontinuation, monitoring for return of symptoms at each step. 1

Standard Tapering Protocol

Stepwise dose reduction:

• If currently on 15 mg daily: reduce to 12.5 mg for 2 weeks, then 10 mg for 2 weeks, then 7.5 mg for 2 weeks, then 5 mg for 2 weeks, then 2.5 mg for 2 weeks, then discontinue 1
• If currently on 10 mg daily: reduce to 7.5 mg for 2 weeks, then 5 mg for 2 weeks, then 2.5 mg for 2 weeks, then discontinue 1
• If currently on 5 mg daily: reduce to 2.5 mg for 2 weeks, then discontinue 1

The FDA label for norethindrone acetate specifies dose escalation in 2.5 mg increments every 2 weeks when initiating therapy for endometriosis, and this same interval should be used in reverse for tapering 1. This approach mirrors the physiologic adjustment period needed for hormonal changes.

Monitoring During Taper

Assess at each dose reduction for:

• Return of original symptoms (abnormal bleeding, pelvic pain, dysmenorrhea) that prompted treatment 1, 2
• Breakthrough bleeding or spotting, which typically occurs within 3-7 days after dose reduction 1
• Pain recurrence in endometriosis patients 2

Schedule follow-up visits every 2-4 weeks during the taper to evaluate symptom control 2. If symptoms recur at any dose reduction, maintain the current dose for an additional 2-4 weeks before attempting further reduction 2.

Clinical Context and Rationale

The 2-week interval between dose reductions allows adequate time to assess endometrial response and symptom control 1. Norethindrone acetate produces secretory transformation of the endometrium, and withdrawal bleeding typically occurs 3-7 days after discontinuation or dose reduction 1. This physiologic timeline guides the tapering schedule.

For patients who were on norethindrone acetate for endometriosis suppression at 15 mg daily for 6-9 months, the full taper will take approximately 10 weeks 1, 2. One case report demonstrated successful symptom suppression with 5 mg daily for 4 years, suggesting that some patients may benefit from maintenance at lower doses rather than complete discontinuation 2.

Special Considerations

If breakthrough bleeding occurs during taper:

• This is expected and typically resolves within 3-7 days 1
• Continue with the planned taper unless bleeding is excessive or prolonged beyond 7 days 1

If original symptoms recur:

• Pause the taper at the current dose for 2-4 additional weeks 2
• If symptoms persist, consider returning to the previous higher dose 2
• Some patients may require long-term maintenance at a lower dose (2.5-5 mg daily) rather than complete discontinuation 2

For patients on combination therapy:

• If norethindrone acetate was used with transdermal estradiol, the progestin should be tapered while maintaining estrogen to prevent unopposed estrogen effects 3
• Micronized progesterone is preferred over norethindrone for long-term hormone replacement due to lower cardiovascular and thrombotic risk 3

Common Pitfalls to Avoid

Do not abruptly discontinue norethindrone acetate after prolonged use (>3 months), as this can cause sudden return of symptoms and irregular bleeding 1, 2. The gradual taper allows the hypothalamic-pituitary-ovarian axis to resume normal function progressively.

Do not use a fixed timeline that ignores individual patient response—the taper must be adjusted based on symptom recurrence, not a predetermined schedule 2. Some patients may need slower tapers with 4-week intervals between reductions rather than 2-week intervals 2.

Do not assume all patients need to reach zero—for conditions like endometriosis or accessory and cavitated uterine mass (ACUM), long-term low-dose maintenance (2.5-5 mg daily) may be appropriate for patients who are poor surgical candidates or prefer medical management 2.