Our menstrual cycle is a monthly reminder that we are cyclical beings. It affects our energy and mood which you're likely familiar with, especially if you suffer from PMS or PMDD. However, our menstrual cycle also affects our immune system, making our immune system cyclical as well.
When is your immune system strongest each month?
Inner Spring: The Follicular phase
The time between your period and ovulation is known as the follicular phase, and it is like your inner spring! Your energy is starting to come back, spring cleaning feels like a good idea and you are ready to venture out into the world after feeling more reclusive and needing more rest during menstruation.
Your immune system is also strongest at this stage of your cycle. You tend to have higher levels of antibodies and also an increased inflammatory response. Rising levels of oestrogen during this phase of our cycle may be responsible for this increased immunity.
This can be challenging if you have an autoimmune disease, as symptoms can flare up at this time. But it is also the time when you are much less likely to catch a cold or flu because the healthy inflammation and increased levels of antibodies mean it's easier for you to fight infection. (1)
Inner Summer: Ovulation
The middle of our cycle, when we ovulate, is like our own inner summer. We are blooming like a flower, and buzzing with energy for the most part. We are also riding off the back of the oestrogen increase of our follicular phase. However, it wears off quickly after ovulation when our oestrogen levels take a dive along with associated antibody increase and that helpful bit of inflammation.
When is your immune system weakest?
Inner Autumn: The luteal phase
So, this makes way for our luteal phase, also known as our inner autumn, and unsurprisingly the time when we are more likely to get sick and catch a cold. After you ovulate, progesterone increases. Even though oestrogen rises again in the luteal phase, progesterone rises more and gives you a higher ratio of progesterone to oestrogen.
Progesterone has so many benefits, my favourite being its calming effect! But it is also linked with the down-regulation of the immune system, and for good reason, evolutionarily speaking. One of progesterone's main tasks is to get the uterus ready to accept, implant, and maintain a fertilized egg. Progesterone also prevents muscle contractions from happening in the uterus that would cause a woman's body to reject an egg.
The inflammatory response dampens down now too, potentially preventing immune interference with conception. While this has a positive effect on many chronic conditions, it is not ideal for your immune system - as we said, inflammation is actually really important in acute instances, like fighting a pathogen!
Research also suggests that you may be more likely to catch a cold right before your period, in the late autumn stage right at the end of your luteal phase, as your levels of certain immune cells, including regulatory T cells, are reduced at this time. (1)
What is the deal with period colds?
Inner winter: Menstruation
Many women find that they get sick during their period; but technically the immune system is more active again at this time, so what is the deal with these period colds?
Well, it could be a matter of timing: you are more likely to pick up a bug during those last pre-menstrual days. And pathogens generally take a few days to incubate before symptoms appear. Hence the delayed reaction!
But the good news is that rest is really important for helping you to fight infection, and it is also one of the best things to do while you are bleeding! So, if you do get a cold during your period, take it as a sure sign that you need more rest! It doesn't mean you have to stay in bed all day, but as much as possible carve out time around menstruation to rest!
My top tip:
If you are dealing with symptoms of excess oestrogen, Agnus castus can help, alongside reducing your exposure to plastic.
A note about hormonal contraceptives
These hormonal shifts that affect our immune system are generally suppressed if we take hormonal birth control. If you are on the pill and still bleed each month, remember that is a withdrawal bleed rather than a period. So, it can be harder to pinpoint when your immune system is stronger or weaker, when you do not have a true menstrual cycle. Understanding your cyclical immunity is just one of the few ways that your menstrual cycle can act like a superpower.
It is also worth noting that research has found that use of combined oral contraceptives is associated with an increase in autoimmune conditions like multiple sclerosis, ulcerative colitis, Crohn's disease, Systemic Lupus Erythematosus, and interstitial cystitis. They also found that progesterone-only contraceptives were associated with what is called progesterone dermatitis, eczema and contact dermatitis, pruritis (itchy skin), alopecia, acne, and urticaria, as well as joint pain and joint diseases like arthritis. (2)
So, from that bit of research, it seems to me that this monthly fluctuation in our immune system is really important for our overall immune health. Yes, we might be more likely to get a cold just before our period, but those natural hormonal fluctuations also seem to be helpful in maintaining healthy immune function and reducing our susceptibility to autoimmune conditions.
Siobhán’s herbal advice for immune support
If you are prone to catching a cold before your period, I'd really recommend taking Echinacea. You can take it throughout your cycle, but it is especially important at ovulation and in the second half of your cycle. If you do come in contact with a pathogen during your luteal phase, Echinacea will give you the extra support needed to fight off the infection, reduce your symptoms and reduce the amount of time you are feeling sick.
