Alarming effect smoking cannabis can have on your period

Periods are already unpredictable enough without having to think about the ways everyday habits might be influencing them during a tough time of the month, but a new study has revealed what happens when you smoke cannabis during your cycle.

When it comes to a period itself, any cycle changes from a later bleed to heavier cramps can come down to a variety of things: stress usually takes the blame first, followed by sleep, food, hormones, and whatever else life has thrown at you lately.

However, if you offset some of that aforementioned stress by smoking marijuana and puffing on a standard tobacco cigarette during your period, this small study diving into the topic has revealed an effect that’s rather unexpected.

Researchers looking at women who co-used cannabis and tobacco found they had a significantly shorter luteal phase than women who only used tobacco. That is the part of the menstrual cycle after ovulation, and before the next period.

Researchers found a cycle change among women using both cannabis & tobacco (Getty Stock Images)

In the study, it averaged 11.4 days in the co-use group compared with 16.8 days in the tobacco-only group.

The study, published in J Addict Med, examined 52 premenopausal female smokers aged 18 to 50 who were trying to quit. Of those, 13 women reported current marijuana and tobacco co-use, while 39 used tobacco only.

Participants used urine luteinising hormone tests to help identify ovulation, allowing researchers to estimate the follicular and luteal phases of the menstrual cycle. While the study did not find significant differences in follicular phase length or total cycle length, the shorter luteal phase stood out.

That’s because the luteal phase is linked to progesterone, a hormone that plays an important role in the menstrual cycle and fertility. The authors said a shortened luteal phase may mean less progesterone is produced, which could potentially make it harder to get pregnant or maintain a healthy pregnancy.

The shortened luteal phase could have implications for fertility, researchers said (Getty Stock Images)

However, the findings come with some very important caveats. First of all, the sample size was small, marijuana use was recorded only as a yes-or-no self-report, and researchers did not collect details on how often participants used it, how much they used, or exactly when.

Secondly, hormone levels were not available for this analysis, meaning the study cannot prove that marijuana directly caused the change.

There was also later commentary attached to the paper questioning the design, which makes it even more important not to treat the findings as the final word.