protein powder and menstrual cycle

Whether it’s soy, hemp or whey, protein powders are a regular part of many women’s diets. And while these powders have their benefits, it’s important that we also discuss the link between protein powder and menstrual cycle irregularities (such as delayed periods).

You see, just like everything else that we ingest (be it food or other supplements) protein powders can affect our hormones. 

And since the menstrual cycle is regulated by hormones, that means protein powders can also mess with our periods.

Now, this is not to say that protein powders or shakes are evil. Nor does this mean that they’re the direct cause of period problems. 

But they can contribute to menstrual cycle problems (just as other dietary and lifestyle factors can also be contributing factors).

To understand exactly protein powder can contribute to menstrual issues, we’re going to look at:

  • what’s really in protein powders.
  • their effect on our hormones.
  • which types to buy.
  • how to use them correctly.

Having a clearer understanding of all of the above will allow you to enjoy protein shakes while also supporting your hormones and monthly cycle.

Note: this post contains affiliate links and I earn a commission (at no additional cost to you)  if you use them to make a purchase.


protein shakes and powders can affect your period

1. Increased Workload for The Liver

According to Harvard Health, some protein powders contain toxins like (source):

  • heavy metals (for example mercury, lead and cadmium).
  • BPA (a known hormone disruptor that is commonly used in plastic bottles, bowls and other containers).
  • pesticides.

In some cases these toxins are present in small amounts, while in other cases they’re present in excessive levels.

Most notably, some protein powders contain as much as 25x the allowed limit of BPA.

All of these toxins are harmful for your hormones and period because they increase the workload on your liver.

Now, in case you didn’t know, the liver has multiple jobs that include:

  • removing toxins from the blood.
  • metabolizing estrogen.
  • making hormones (such as converting thyroid T4 hormone to T3).

The liver is extremely efficient at doing it’s job…but if there are too many toxins coming every day, then the liver can become overworked and sluggish.

And if that happens, more toxins stay in your bloodstream where they can do more harm.

Also, a sluggish liver means the liver isn’t metabolizing estrogen, which can lead to excess estrogen, as well as an imbalance in your estrogen to progesterone ratio.

Furthermore, a sluggish liver can throw your thyroid hormones out of balance.  

Since the thyroid regulates all metabolic processes, this means that ovulation and your period can be negatively affected.

2. Whey Protein and Other Powders May Contribute to Estrogen Imbalance

Animal-derived proteins (such as whey and casein) are some of the most popular and affordably priced powders on the market.

But unfortunately, these powders have been shown to contain small amounts of estradiol, which is a type of estrogen.

In addition, many cows are injected with growth hormones, which could also be present in your powder.

As women we’re already programmed to produce plenty of estrogen.

So, using the wrong type of protein powder could do more harm than good for your hormones.

Furthermore, protein powders can create more estrogen imbalance because of pesticides and soy protein.

This can happen because:

  • most pesticides are estrogen-based compounds that mimic and interfere with the function of our natural estrogen (1, 2, 3). 
  • the majority of soy on the market is genetically modified. GMO soy is designed to resist pesticides, which means you can spray it with more pesticides than you would a non-GMO soy. As a result, GMO soy can end up with a lot more pesticide residue (which will also be present in soy powder).
  • some women don’t react well to soy (whether this is strictly due to the pesticides or the phytoestrogens exclusively, no one really knows).

As you can see there are many potential “traps” in protein powder. So, it’s up to each of us to ensure that we use these powders wisely (if at all).

By the way, for a more in depth look at this particular topic, be sure to read this article on whey protein and estrogen dominance.

3. Protein Powders May Inadvertently Lead to Nutritional Deficiencies

Sometimes protein powders are marketed as a perfect meal substitute.

But the truth is, they’re simply not a good meal replacement.

Sure, a protein shake can keep you feeling full for longer.

But eating a meal isn’t just about feeling full: it’s about nourishing your body.

And the problem with protein powders is that they don’t contain a full spectrum of nutrients. They only contain protein. 

A truly healthy meal substitute should also contain vitamins, minerals, antioxidants, enzymes, fatty acids, carbs and so on.

Even a really good, fortified protein powder still isn’t a truly balanced meal substitute.

So, over-relying on protein powder can inadvertently lead to nutrient deficiencies because you’re substituting nutrient-dense foods for one nutrient (protein).

And even though the amino acids in proteins play a role in hormone balance, you still need all the other macro and micronutrients for sustainable hormone balance, ovarian function and menstrual health.

So, basically just remember that even the best pea or hemp protein concentrate is nowhere close to a real pea or hemp.

4. Protein Powders May Contribute to Bloating and Digestive Issues

Both plant and animal protein powders can contribute to bloating and other GI issues.

One reason why this may happen is that the powder contains whey or casein, which are both derived from milk. 

Some of the lactose in milk ends up in the protein powder. And if you’re lactose-intolerant, then these powders can cause digestive issues.

Another reason why bloating can occur is that your gut is having a hard time digesting the powder.

Remember that protein powders are highly processed. Sometimes there are fillers, thickeners, gums and sweeteners added to them that can be hard on your gut and digestive system.

And if your body can’t process these ingredients, then they fester in there, overload the liver (again!) and can indirectly slow down processes that affect hormone balance.


protein shake during your period

You can drink protein shakes during your period as well as any other time of the month, so long as you follow these general guidelines:

  • DO buy organic protein powder as much as possible.
  • DO read the label on animal-derived protein powders. Ideally they should be grass-fed, pasture-raised, antibiotic-free and hormone-free cows. 
  • DO avoid soy protein as much as possible. Soy is a long and complicated subject for women’s hormones. Overall, fermented soy seems to be better, while unfermented soy (such as the one in protein powder) seems to be the worst.
  • DON’T use legume-based powder (like pea protein) if you usually have a hard time digesting legumes. This will only give you more bloating, gas and GI issues.
  • DON’T use powders that are sweetened with sucralose, aspartame or other artificial sweeteners. They can contribute to digestive issues.
  • DON’T assume “natural flavors” in your vanilla or chocolate powder are actually natural. Sometimes natural flavors can be a less-than-healthy ingredient like MSG (another hormone disruptor which I discuss in this post on MSG and hormones). 
  • DO buy a plant-based, organic, naturally sweetened powder if you want something that has a vanilla or chocolate flavor. By purchasing the cleanest powder you can find, you minimize the total number of toxins that you’re exposed to. Here’s one that I suggest looking into.
  • DO drink protein shakes just a few times a week (say every 2 days). And stick to 1 a day.
  • DO use whole hemp seeds as a sub for protein powder. They’re loaded with proteins and hormone-friendly fats. Just add a tablespoon or two to your smoothies, oatmeal or other types of porridge.
  • DO take a break from consuming protein powders if you find that all of the above tips still aren’t improving how you feel. Switch to whole food sources of protein so that you can get more nutrients into your body.

If you’d like to dive deeper into the topic of food and periods, be sure to read this article on what to eat during each phase of the menstrual cycle. It provides a good overview of foods that support the body during the follicular and luteal phases of your cycle.


Can protein shakes change your mood?

According to a study from the University of Sydney, over-consumption of protein powders can lead to depression (as well as increased cravings, weight gain and a shorter lifespan).

Can I drink a protein shake twice a day?

Technically you can drink two protein shakes a day. However that may not be the wisest choice because it exposes you to more of the side effects that we’ve covered in this article.

chocolate protein powder and menstrual cycle


Even though protein powders can help in the short-term with weight loss, they can create more problems for your period and your hormones if used incorrectly.

Also, because they’re not a complete food, every time you replace a meal with a protein powder, you’re depriving yourself of a rainbow of nutrients that you would have received from a balanced meal.

Personally, I do not use protein powders. But I do understand that they offer convenience.

Therefore, if you’re going to use them, use them wisely.

And if you see any signs of imbalance creeping up, then ditch the powder in favor of a more complete food.

Hey there! Curious about supplements for women’s hormones? Here are my top picks (in-depth reviews for each is available here):

  • Hormone Harmony: Formulated for all around-hormone support, this supplement combines cortisol/stress lowering herbs (aka adaptogens), with herbs for nervous system support, insulin sensitivity and more. it’s no wonder it has 12,000+ (mostly glowing) reviews! Get $10 OFF with code HAPPYYOU076057.
  • Live It Up (formerly Enso) Supergreens: after getting a free sample from the company, I was seriously impressed by this greens powder. I love it because it has lots of mineral-rich and nutrient-dense greens and nothing else. The minty flavor is 100% from mint, no synthetic flavors (or other additives). I also love that it has no adaptogens (which my body is not a fan of lately). Think of this as your green, multivitamin/multimineral.
  • Moon Balance: this powder combines some of the best herbs for menstrual support, such as hibiscus, maca and shatavari. If your cycle is off balance and you struggle with things like PMS, period pain and other menstrual imbalances, this is one to check out.
  • Maca Root Powder: in the single herb category, maca is worth paying attention to. It has traditionally been used in Peru for hormone support (in men and women). Research and anecdotal reports indicate that this root vegetable helps with libido, anxiety, hot flashes, menstrual health and more.

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Best Protein Powder For Hormonal Balance: Top Brands and What to Look For

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