A progestin challenge
🌙 Why might you be offered progesterone when your periods have stopped?
If your periods have been absent for a while (amenorrhoea), one of the first things we often want to understand is:
👉 What are your hormones doing in the background?
There are a few common reasons periods can stop, including:
• Not ovulating regularly (e.g. PCOS)
• Hormonal changes (e.g. perimenopause)
• The brain temporarily “switching off” ovulation (often related to stress, weight changes, or high physical demand — sometimes called hypothalamic amenorrhoea)
At the beginning, it’s not always obvious which of these is the cause — so we often start with a simple, helpful test.
🧭 What is a progestogen (progestin) challenge?
A progestogen challenge involves taking a progesterone-type medication for about 10 days, then stopping it.
After stopping, we watch to see if you have a bleed (similar to a period).
🔍 What can this tell us?
This small step gives us surprisingly useful information:
• ✅ If you have a bleed:
→ Your body is making enough estrogen to build up the uterine lining
→ The most likely issue is not ovulating regularly
• ❌ If you don’t bleed:
→ Estrogen levels may be low, so the lining hasn’t built up
→ This can suggest a hypothalamic cause (where the brain has paused ovulation), or less commonly other hormonal conditions
→ It tells us we need to look a bit deeper
👉 Either outcome is helpful — it guides what we do next.
💊 Why is Provera often used first?
A commonly used option is Provera (medroxyprogesterone) 10 mg daily for 10 days.
It’s often chosen because:
• It is reliable at triggering a withdrawal bleed if estrogen is present
• It gives a clear diagnostic signal
• It has been used for many years as a standard first-line approach
🌿 What about body-identical progesterone (Utrogestan)?
Utrogestan is a form of micronised progesterone, which is closer to the hormone your body naturally produces.
It may be used longer-term care (but there is limited data) — but for this specific test:
• It typically requires higher doses (300–400 mg) to have the same effect
• These doses can feel more sedating or harder to tolerate
• It may be less consistent as a diagnostic test
👉 For this reason, many clinicians use Provera first for clarity, then consider Utrogestan later if ongoing, more physiological support is needed.
🛡️ Why does this matter?
The reason behind your missing periods matters for your health:
• If your body is making estrogen but you’re not ovulating:
→ The uterine lining can build up over time
→ Progesterone helps shed and reset the lining safely
• If estrogen levels are low:
→ The focus shifts to why hormone production is reduced, rather than lining protection
❤️ The bottom line
This isn’t just about “bringing on a period.”
It’s a simple, low-risk way to:
• Understand your hormone pattern
• Narrow down the cause of absent periods
• Guide the next steps in your care
And importantly:
👉 You may or may not have a bleed — and both outcomes are useful.
⚠️ Possible side effects
Some people notice:
• Bloating
• Breast tenderness
• Mood changes
These are usually temporary and if needed, the type, dose, or timing can be adjusted.
This approach reflects standard clinical guidelines used internationally to investigate absent periods, including GP and endocrine society recommendations
