Creatine for women over 40

For women over 40 who lift weights or do other resistance training, creatine monohydrate has reasonable evidence for adding a little more muscle and strength than training alone, at a low cost and with a good safety record in healthy people. The bone results in postmenopausal women are mixed, the memory findings are early, and without exercise creatine does little.

What it is

Creatine is a compound the body makes from three amino acids in the kidneys and liver, and that people also get from meat. Muscle stores it as phosphocreatine, a quick energy reserve for short, intense effort. Supplementing raises those stores, which is why creatine has been one of the most studied sports supplements since the early 1990s. It is not a hormone or a steroid.

One review by researchers who study creatine in women reports that women have 70 to 80 percent lower endogenous creatine stores than men. Two of its four authors advise a creatine manufacturer, a common situation in this field that is worth knowing as you read the evidence.

Why women in midlife take it

Muscle mass and strength decline with age, and the menopause transition is when many women start paying attention to bone; for background on the transition itself, see What is perimenopause?. Resistance training is considered the cornerstone of preserving muscle with age, and creatine is promoted as a way to get more from it. More recently it has been marketed for brain fog, mood and energy in perimenopause, which is where the evidence is thinnest.

What the evidence shows

Muscle and strength, with training. A 2017 meta-analysis pooled 22 randomized trials with 721 men and women whose average ages ranged from 57 to 70. Participants did resistance training two to three days a week for 7 to 52 weeks with creatine or placebo. Creatine added about 1.37 kg more lean tissue than placebo and produced greater gains in chest press and leg press strength. The strength effects were modest in size.

Muscle, without training. The creatine review by Antonio and colleagues concludes that creatine alone is unlikely to produce substantial gains in strength or function in older adults. It cites a trial in which postmenopausal women took 3 g a day for 2 years without a training program and did not gain lean mass.

Bone. A 12-month trial randomized 47 postmenopausal women (average age 57) doing supervised resistance training three days a week to creatine at 0.1 g per kg of body weight daily or placebo; 33 were analyzed. Bone density at the femoral neck fell 1.2 percent with creatine versus 3.9 percent with placebo, and bench press strength rose 64 versus 34 percent.

A larger 2-year follow-up trial then randomized 237 postmenopausal women (average age 59) to creatine at 0.14 g per kg daily or placebo during resistance training three days a week and walking six days a week. Creatine had no effect on bone mineral density at the femoral neck, total hip or spine. It did preserve two measures of femoral neck geometry linked to bone bending strength, and it slightly improved walking speed. It did not improve bench press or hack squat strength. Among women who completed the protocol, lean mass increased more with creatine. The fair reading is that creatine does not replace proven bone treatments, and its effect on fracture risk is unknown.

Memory. A 2023 meta-analysis of 8 randomized trials in healthy people found creatine improved memory test scores overall (standardized mean difference 0.29), with a larger effect in adults aged 66 to 76 and no effect in people aged 11 to 31. Doses ranged from about 2.2 to 20 g a day for 5 days to 24 weeks. Other researchers published a letter arguing the analysis double-counted data and may have overstated the effect. No trial has tested creatine for perimenopausal brain fog.

Mood, hot flashes, sleep. There are no trials in perimenopausal women for these symptoms.

Dose and form used in studies

The standard maintenance dose is 3 to 5 g of creatine monohydrate a day, or about 0.1 g per kg of body weight. A “loading phase” of 20 to 25 g a day split into four or five doses for 5 to 7 days fills muscle stores faster but is not required: in a classic comparison, 3 g a day for 28 days produced the same rise in muscle creatine (about 20 percent) as 20 g a day for 6 days. The bone trials above used higher, weight-based doses of 0.1 to 0.14 g per kg.

Monohydrate is the form used in nearly all research. The Antonio review found no peer-reviewed evidence that creatine salts, ethyl ester, buffered creatine, creatine nitrate or other forms raise muscle creatine more than monohydrate at equal amounts; most deliver less creatine per gram.

Safety, interactions and who should be careful

The International Society of Sports Nutrition position stand describes creatine as safe and well tolerated in healthy people in short- and long-term use, at doses up to 30 g a day for 5 years. The most common side effect is water retention in the first several days, mainly with loading. Single doses above 10 g may cause stomach upset. Training studies have not found increases in body fat.

Kidneys: controlled research shows no kidney damage in healthy people at recommended doses. Case reports of kidney problems involved pre-existing kidney disease, other medications or supplements, very high doses or steroid use. Creatine can raise blood and urine creatinine, which labs use to estimate kidney function, so a higher creatinine on routine bloodwork may reflect the supplement rather than a kidney problem. Tell whoever orders your labs.

Interactions with hormone therapy, SSRIs, thyroid medication or blood thinners have not been specifically studied, and none are described in the reviews above. Include creatine on your medication list.

Talk to your clinician first if you have kidney disease or take medicines that affect the kidneys, or if you are pregnant or trying to conceive.

How to choose a product

Choose plain creatine monohydrate powder or capsules with creatine as the only listed dietary ingredient. Check the Supplement Facts panel for grams of creatine per serving; capsules often contain under 1 g each, so a 3 to 5 g dose may take several. Avoid pre-workout or “women’s formula” blends where creatine sits inside a proprietary total alongside stimulants. Because sports supplements are a category where undeclared ingredients turn up, a third-party mark such as NSF Certified for Sport or USP Verified adds reassurance about contents.

Bottom line

If you strength train, 3 to 5 g a day of creatine monohydrate is a well-studied, low-risk way to support muscle and strength in midlife, provided your kidneys are healthy. It will not do the training for you, it is not a bone treatment, and the brain claims are still early. For bone health and other midlife concerns, a clinician who knows menopause can put creatine in context; see how to find a menopause specialist or the clinician finder.