
Progesterone is beneficial because it lightens periods. It also reduces inflammation, regulates immune function, and supports healthy thyroid, brain, bones, and breasts.
Do you make enough progesterone? Are you sure?
The only way to make progesterone is with ovulation and a healthy luteal phase.
What is a luteal phase?
A luteal phase is the approximately 10-14 days between ovulation and the period. It’s named after the corpus luteum, which is the temporary ovarian gland that forms after an egg is released. Having a healthy corpus luteum is the only way to make progesterone.
You can detect your luteal phase by tracking your basal body temperature, which is an under-the-tongue temperature first thing in the morning before you get out of bed. Progesterone increases resting temperature by about 0.3℃ so a luteal phase is higher temperatures for 10-14 days followed by a bleed. If your temperatures go up but you don’t get a bleed, then you’re pregnant. There’s no third option because it’s not possible to ovulate but then not bleed except with the hormonal IUD, uterine ablation, or hysterectomy.
Finally, if your temperatures don’t go up, then it’s an anovulatory cycle and you make no progesterone. Anovulatory cycles are also called hormone imbalance, dysfunctional uterine bleeding, unopposed estrogen, or estrogen dominance (a term I don’t use).

Four signs of progesterone deficiency
- A short luteal phase or no luteal phase, because a healthy luteal phase should be at least 11 days.
- Low temperatures in the luteal phase, because progesterone raises body temperature.
- Fertile mucus in the luteal phase, because progesterone dries up fertile mucus.
- Spotting in the luteal phase, because progesterone helps to hold the uterine lining.
Testing for progesterone deficiency
The best way to test for progesterone is to track basal body temperature. You can also measure progesterone as serum progesterone on a blood test.
Serum progesterone above 4 ng/mL (13 nmol/L) confirms ovulation but ideally, it should be at least 8 ng/mL (25 nmol/L). The more progesterone, the better. It’s not possible to have “too much” progesterone, except in the case of exogenous supplementation (taking progesterone).
- There’s no progesterone before ovulation, so you need to test about a week before your period actually comes. Read The right way to test progesterone.
- There’s no progesterone if you’re on almost any type of hormonal birth control because contraceptive drugs suppress ovulation and progestins are not progesterone.
Need more progesterone? You can supplement natural progesterone as a cream or a capsule. Or you can make progesterone yourself.
How to make more progesterone
The only way to make progesterone is to consistently ovulate every month and to do that, you need to support overall general health because ovulation is a monthly report card of health.
For example, to be able to ovulate, you need to identify the underlying obstacle to ovulation and correct that. Common obstacles include stress, inflammation, thyroid disease, insulin resistance, nutrient deficiency, and/or undereating.
Read:
- Are you eating enough to get a period?
- Have you lost your period to a low carb or keto diet?
- Why a vegan or exclusively plant-based diet can be a problem for periods.
One hundred days to ovulation
The road to progesterone is long. It takes one hundred days for ovarian follicles (eggs) to journey all the way to maturity and cross the finish line to ovulation. In other words, it takes one hundred days of being healthy and fully nourished to finally achieve ovulation and progesterone.
That means that there can be a delay of a few months between your health and your period. Your progesterone deficiency now could be telling the story of stress or undereating that started months ago.
Vitex agnus-castus (chasteberry or chaste tree)
Vitex is a herbal medicine that promotes ovulation and therefore can enhance progesterone, but only if you’re fully nourished. Vitex is effective for both progesterone-deficient and progesterone-sensitive conditions such as PMS and PMDD. For more information about PMDD, read Why progesterone is both good and bad for mood.
👉 Tip: Be careful with Vitex if you have PCOS because it can worsen the condition. See my post: The dos and don’ts of Vitex, and join in the conversation.
Roadmap to progesterone
- Be well nourished with calories, protein, carbohydrate, fat, iodine, and zinc.
- Correct underlying inflammatory issues such as dairy sensitivity, gluten sensitivity, mast cells and histamine issues, leaky gut, thyroid disease, or insulin resistance.
- Reduce stress.
- Consider taking ovulation-promoting herbs such as Vitex (chaste tree) or peony.
- Remember the hundred days to ovulation and play the long game.
For more information, check out Period Repair Manual.
