Should women be taking creatine?
As one of the most common dietary supplements in the sports nutrition world, I would be surprised if you haven't at least heard of creatine. For years it has been something I have largely ignored, as I don't have much interest in sports nutrition. However, I've recently been very intrigued by the benefits of creatine, specifically in women, beyond just optimizing athletic performance. It may not surprise you that a majority of the research in sports nutrition is on men. But as the amazing Dr. Stacy Sims puts it, "women are not small men", so just because research finds that creatine may be beneficial for men, doesn't mean it is for women. Luckily, there has been more and more coming out on the effects of creatine in women. Researchers are finding it's a quite safe and effective supplement that I believe most women should at least consider looking into, and that Dr. Sims thinks is "the most important supplement many women still aren't taking".
In this blog I'll cover:
what creatine is
various benefits of creatine found in the research for women
potential side effects
what to choose and dosing
what is creatine?
Creatine is a substance that is naturally produced endogenously (inside the body) through the metabolism of these 3 amino acids (aka proteins): glycine, arginine, and methionine. Its main role is to help your muscles access additional energy during higher-intensity exercise/lifting, which makes sense as about 95% of creatine is stored in skeletal muscle. The remaining 5% is found in other organs such as the brain, which is why creatine might help promote brain health and mood (more on this later).
What intrigues me about creatine in women is that women have 70-80% less endogenous production of creatine compared to men. That's a HUGE difference! Information like this makes me wonder if this is a piece of the puzzle as to why women tend to have weaker muscles and bones compared to men (beyond the obvious differences in sex hormones like testosterone and estrogen).
We can obtain creatine in the diet, but mostly through meat and fish. So if you don't eat animal proteins, this is just the first reason why you might want to consider creatine, as vegetarians have been found to have lower concentrations of creatine in the body.
A recent review on creatine stated, "creatine supplementation may be of particular importance during menses, pregnancy, post-partum, during and post-menopause". So... almost our entire lives! It also mentioned that "lower endogenous levels [of creatine] have a greater capacity to increase creatine following supplementation". This means that since women naturally have lower endogenous levels of creatine, they could actually benefit MORE from supplementation.
the research
Muscle strength:
A majority of creatine studies in women are on collegiate athletes. I know most of you aren't college or professional athletes, but a colleague of mine back in Asheville always said, "if you work out, you're an athlete". And I liked that mindset! In general, creatine helps improve athletic performance and increase strength. Now I did find one study that found that 10 weeks of creatine significantly increased lower body strength and fat free mass (fat free mass = all of your body parts, such as muscle or bones, that don't contain fat) in healthy, sedentary females performing strength training compared to those strength training without supplementation of creatine. So creatine helped build strength in non-collegiate athlete females too!
It's important to note that there are studies (like this one and this one) that have shown no benefit from creatine supplementation. The authors think this might have been from an insufficient loading dose (more on dosing later), an inadequate amount of training, or biological differences in creatine uptake. However, due to its low risk-to-benefit ratio, and studies showing effectiveness for increasing strength and power in both trained and untrained females, I'm starting to recommend it more and more for my clients looking to build muscle and improve their metabolism.
Fertility/Pregnancy:
There are no human studies on taking creatine during pregnancy, but it has been found that low creatine stores might be associated with preterm birth or low birth weight. Mouse studies suggest that creatine supplementation could help protect against brain injury in the baby due to lack of oxygen during labor and delivery. Here are two great reviews written in 2014 and 2021 that provide a ton of information on the role of creatine in women's reproductive organs and the reasons why creatine supplementation could be very beneficial for fertilization and during pregnancy. They are long and scientific, and quite honestly I have not read the entirety of them, but I found a lot of the information fascinating and I recommend giving them a scroll! While it's likely not harmful to take creatine during this time, if it doesn't feel like a good idea, you could focus on ensuring you are consuming enough animal proteins to get your daily dose of creatine!
Menopause:
Due to hormonal changes in menopause, it's common to see an increase in bone and muscle loss. Creatine supplementation may be able to offset this loss of muscle and overall strength, and support bone density! It's proposed that creatine can increase osteoblast activity, the cells that participate in bone formation! To make sure I'm not cherry-picking information, I do have to mention there are studies also finding no benefit on bone health in older adults as well! I read a review that suggests the bone health benefits from creatine might just be a by-product of the primary benefit of building strength and having stronger muscles, leading to being able to lift heavier with strength training. If you are lifting heavier, you have stronger bones!
Mood, depression, cognitive health:
A 2020 study found that the prevalence of depression was 31% higher in adults with the lowest dietary creatine intake. And guess what? This negative association of creatine intake with depression was strongest in women. Also, omen experienced faster improvements in their depression when combining creatine with their anti-depressant, vs taking an anti-depressant alone.
During the luteal phase of the menstrual cycle (the 2nd half, before our period starts), our estrogen and progesterone hormones peak, and then drop down to their lowest point, which stimulates our period to start. These significant hormonal changes alter our neurotransmitters (brain hormones like GABA, serotonin, and dopamine), causing a change in mood. Creatine might help offset those changes, since it has been found to impact neurotransmitters!
Finally, creatine might also help with brain processing in those who are sleep-deprived or stressed.
potential side effects
Creatine is a very safe, low-risk supplement and the potential for adverse side effects have been mostly groundless. In the loading phase (described below), weight gain may occur purely due to an increase in cellular hydration (water weight) . However this has been seen to occur more in males, and shouldn't last long and should not be a reason to avoid supplementation.
dosing
So there are two ways to take creatine. A lot of research includes a loading dose of 20g/day of creatine (taken as 4 separate doses of 5g throughout the day, every four hours), and then an ongoing dose of 5g/day. You can also just start with the low dose of 5g/day ongoing. Not doing a loading dose will likely result in less initial water retention in those first few days.
Absorption is best taken as a powder mixed in water compared to a capsule or chewable. The powder truly doesn't taste like anything, I mix it straight into water. You do need to occasionally shake/stir it to keep it mixed up well, but otherwise, you don't really know it's there! You could also mix the powder into yogurt, oats, a smoothie, applesauce, or any other beverage.
Stick with creatine monohydrate as this will be best absorbed. Personally, I've only used Thorne, and really like that brand, but here are a few options to take a look at.
If you don't want to take creatine daily, then below are the times I would recommend it most:
before, during, or after performing high-intensity activity or strength training, with the goal of building muscle
when you are sleep-deprived and need your brain to function better
when you are experiencing mood changes from your cycle, typically the week or two before your period