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What Can Influence Your Cervical Mucus?

Published May 11, 2020 · Updated Sep 17, 2026 · Evidence-based
Quick answer

Age, BMI, fertility medications like Clomid, antihistamines, recent birth control use, and hydration can all reduce the amount and quality of fertile cervical mucus you produce -- mostly by affecting the estrogen levels that drive it.

Weird to talk about in daily life, completely normal to talk about with TTC friends -- so let's talk about cervical mucus (CM).

What fertile CM should look like

If you're trying to pinpoint your fertile window, you want your cervical mucus wet for 2 or more days, ideally with a consistency close to raw egg white. But not every woman gets fertile-quality CM every single cycle. Here's what can get in the way.

Things that can reduce your fertile CM

  • Age: as you get older, you'll have fewer days of fertile-quality CM, since estrogen -- the key hormone behind it -- naturally declines with age.
  • BMI: both low and high BMI are linked to lower estrogen levels, which affects CM production.
  • Fertility medications: Clomid in particular is often prescribed to induce ovulation, but it blocks estrogen receptors in the brain, which can reduce CM. Only about 15% of women on Clomid experience this though.
  • Antihistamines: the same drying effect they have on nasal mucus can extend to cervical mucus.
  • Recent birth control use: if you've just come off the pill, the first few cycles can run drier -- though this effect usually fades quickly.
  • Water intake: fertile cervical mucus is almost entirely water, so dehydration directly affects it. This is the easiest one to fix -- just drink more water.

Six factors that can influence how much (and how good) your CM is each cycle -- and the good news is that at least one of them is completely within your control.

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Common questions

What does fertile cervical mucus look like?

Wet for 2 or more days, with a consistency close to raw egg white -- clear, stretchy, and slippery.

What's the easiest thing I can do to improve my cervical mucus?

Drink more water. Fertile cervical mucus is almost entirely water, so dehydration is one of the simplest, most fixable causes of a dry cycle.

Does Clomid always dry up cervical mucus?

No -- only about 15% of women taking Clomid experience this side effect, even though it's a well-known one.