Seed cycling is a growing trend claimed to balance hormones, boost fertility, and ease symptoms of menopause.

It involves eating flax, pumpkin, sesame, and sunflower seeds at different times of the month to balance certain hormones.

However, despite plenty of anecdotal accounts of its usefulness, scientific evidence to back its claims is lacking.

This article tells you everything you need to know about seed cycling and whether it’s a helpful practice.

Seed cycling is a naturopathic remedy that is claimed to balance hormones by regulating the hormone estrogen in the first half of your menstrual cycle and the hormone progesterone in the second half.

Its purported health benefits include helping regulate periods, reducing acne, treating polycystic ovarian syndrome (PCOS), endometriosis, and infertility, and easing symptoms of menopause, such as hot flashes, night sweats, fatigue, and mood swings.

Some online sources also assert that it can improve thyroid hormone levels, hair health, weight loss, water retention, and cellulite.

The most common method instructs women to eat 1 tablespoon each of freshly ground flax and pumpkin seeds per day for the first 13–14 days of their menstrual cycle, which is known as the follicular phase.

During the second half of their cycle, which is known as the luteal phase, seed cyclers eat 1 tablespoon each of ground sunflower and sesame seeds per day until the first day of their next period when their cycle starts again.

For menopausal and postmenopausal women without a regular menstrual cycle, it’s often recommended to use the phases of the moon as a guide to cycle dates, with day one of their cycle falling on the new moon.

Proponents claim that positive hormonal changes will be noticed after just a few months of cycling.

Summary

Seed cycling is a naturopathic remedy that aims to balance estrogen and progesterone levels by eating flax and pumpkin seeds during the first half of the menstrual cycle and sunflower and sesame seeds during the second half.

The claims about how seed cycling works are inconsistent across different sources. However, the basic idea is that different seeds can promote or hinder the hormones estrogen and progesterone.

Hormones in a normal cycle

In a regular cycle, estrogen is produced during the first 14 days of the follicular phase as eggs in the ovaries ripen (1, 2).

Levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) increase just before ovulation, and estrogen levels drop just after ovulation (1, 2).

Once an egg has been released, the luteal phase starts, and progesterone and estrogen levels gradually increase in a careful balance to support conception and implantation. They drop again before the next period if no implantation occurs (1, 3).

Causes of hormonal imbalance

Most women produce adequate levels of hormones to support a healthy cycle. However, certain health conditions, such as PCOS and hypothyroidism, as well as over-exercising and being under- or overweight, can lead to a hormonal imbalance (4, 5, 6, 7).

Additionally, during menopause, levels of estrogen and progesterone decrease, which increases your risk of heart disease and osteoporosis and can lead to symptoms like hot flashes and weight gain (8, 9).

Seed cycling proposes to not only support those with hormonal imbalances but also those with healthy cycles.

How seeds influence hormones

During the follicular phase, proponents of seed cycling claim that the phytoestrogens in flax seeds can help increase or decrease estrogen levels as needed.

Phytoestrogens are compounds in plants that can mimic the action of estrogen (10).

Additionally, zinc from pumpkin seeds is claimed to promote progesterone production in preparation for the next phase of the cycle.

During the luteal phase, lignans — a type of polyphenol — in sesame are supposed to inhibit estrogen levels from increasing too much. Meanwhile, the vitamin E in sunflower seeds is thought to help boost progesterone levels.

Summary

Seed cycling proposes to balance estrogen and progesterone through the actions of phytoestrogens, zinc, selenium, and vitamin E.

A primary claim of seed cycling is that it can balance your hormone levels through the actions of phytoestrogens from lignans.

Sesame and flax seeds have particularly high concentrations of lignans, packing 834 mg and 294 mg per 3.5 ounces (100 grams), respectively (11).

After consumption, these lignans are converted into the mammalian lignans enterolactone and enterodiol. These phytoestrogens can mimic the action of estrogen or hinder it, depending on the dose (10, 11, 12, 13).

Some small studies in women have linked flax seed intake to improved cycle regularity and hormone levels, a lengthened luteal phase, and reduced cyclical breast pain (14, 15, 16).

However, the estrogen-promoting and -hindering effects of these lignans are relatively weak and have primarily been associated with anticancer properties rather than normalizing hormone balance (11, 12, 17, 18, 19).

In regards to sesame, one 5-week study in postmenopausal women found that consuming 1.8 ounces (50 grams) of sesame powder daily increased levels of some other sex hormones but did not affect estrogen levels (20).

Finally, while adequate zinc and vitamin E intake is necessary for good reproductive health, no solid evidence suggests that getting these nutrients from seeds offers any extra benefits for hormone balance (21, 22, 23, 24).

In general, women with a normal menstrual cycle already produce the correct amounts of hormones. For those with hormonal imbalances, seed cycling is not likely to be the best way to improve symptoms.

Summary

Plant lignans can have a weak effect on estrogen levels, and flax seeds are linked to improved cycle length and reduced breast pain. Still, no evidence associates seed cycling with improved hormone levels.

Some seeds have been found to improve symptoms and hormone status during and after menopause.

In particular, flax seeds have been linked to slight increases in estrogen, improved hormone metabolism, fewer hot flashes, reduced vaginal dryness, and better overall quality of life in menopausal and postmenopausal women (25, 26, 27, 28).

For example, in a 3-month study in postmenopausal women, taking a concentrated supplement that included 100 mg of flax seed extract and black cohosh improved symptoms like hot flashes, nervousness, mood changes, and headaches (29).

In addition, flax seed intake is linked to cancer-fighting properties and a reduced risk of breast cancer in postmenopausal women. Yet, more clinical studies are needed to confirm these findings (30).

Sesame may offer health benefits to postmenopausal women as well.

In one 5-week study in 24 postmenopausal women, taking 50 mg of sesame powder daily improved hormone status and antioxidant and blood fat levels (20).

However, other studies note that lignans, phytoestrogens, and seeds may not be any more effective at improving symptoms of menopause than a placebo, so more research is needed (31, 32, 33).

Neither zinc nor vitamin E have been found to significantly affect menopausal symptoms or hormone levels (34, 35).

Overall, while flax and sesame seeds may offer some health benefits for menopausal and postmenopausal women, no evidence suggests that the doses and timings proposed by seed cycling have any particular benefits.

Summary

Flax and sesame seeds may improve some menopausal symptoms, such as estrogen levels, hot flashes, and vaginal dryness. Still more research is needed. No evidence suggests that the doses and timings promoted in seed cycling provide benefits.

Though evidence to support the claims of seed cycling is insufficient, including flax, pumpkin, sesame, and sunflower seeds in your diet is still a great way to promote good health.

All four seeds are rich in fiber, manganese, magnesium, copper, thiamine, vitamin E, and healthy fats. These nutrients are vital to good health, including reproductive health (36, 37, 38, 39).

Furthermore, flax, sesame, and sunflower seed intake has been linked to improvements in heart disease risk factors, such as high cholesterol and blood pressure levels (20, 40, 41, 42).

Additionally, flax, pumpkin, and sunflower seeds may protect against breast cancer (43, 44, 45, 46).

What’s more, flax seeds are also associated with improved blood sugar control, while pumpkin seed oil may aid prostate and urinary disorders (47, 48, 49).

Finally, sesame seeds are linked to reduced inflammation and may improve athletic recovery and performance (20, 50, 51).

Summary

Though seed cycling may not balance hormones, including seeds in your diet boosts your intake of vitamins and minerals and is associated with a lower risk of certain cancers, as well as reduced inflammation, cholesterol, and blood sugar levels.

Many seeds are highly nutritious and offer a number of health benefits.

Seed cycling involves eating flax, pumpkin, sesame, and sunflower seeds at different times of your menstrual cycle. The practice is claimed to balance certain hormones, boost fertility, and ease symptoms of menopause, among other benefits.

However, evidence to support these claims is either lacking or weak.

For example, the lignans in these seeds are linked to weak effects on hormone levels, as well as only minor reductions in menopausal symptoms and possibly a lower risk of breast cancer.

Nonetheless, eating seeds is still a great way to improve the quality of your diet and overall health.