A 2009 study implicated that creatine supplementation might worsen hair loss.[1] In this RCT, males given creatine experienced a significant increase in their blood levels of dihydrotestosterone (DHT) — an androgen that contributes to hair loss, particularly in males.
Since creatine is one of the few supplements that reliably increases performance, along with boasting a good safety profile,[2] such a side effect would be a most unwanted revelation.
So, how worried should you be that creatine could cause your hair to fall out?
What causes hair loss?
In males, the development of hair loss is relatively well understood. By interacting with hair follicles, DHT can induce hair loss.[3][4] Whether a given hair is more or less likely to fall, because of DHT sensitivity or for other reasons, depends on its location (in male-pattern hair-loss, the crown and hairline thin first) and your genetic heritage.[5][6]
DHT is a metabolite of another androgen: testosterone. An enzyme called 5-alpha-reductase converts free testosterone (testosterone not bound to either serum albumin or sex hormone binding globulin (SHBG)) to DHT.[7] DHT can bind to receptors on the hair follicles of the scalp, causing them to shrink and cease hair production over time.[8][9] Drugs that block the actions of 5-alpha-reductase, such as finasteride (Propecia), can be very effective in preventing hair loss.[10]
In females, the development of hair loss is less well understood. Genetic factors do contribute to female-pattern hair-loss, but the importance played by the genes identified in females is less clear than the importance played by the genes identified in males.[11] Similarly, DHT is thought to play a lesser role in female hair loss.[12] Additional factors, such as estrogen levels, are thought to have some influence on female hair loss, but here again there is conflicting evidence.[13]
Dihydrotestosterone (DHT) and genetics play a prominent role in male-pattern hair-loss, and a lesser role in female-pattern hair-loss. The factors causing female hair loss are less well understood than those causing male hair loss.
Will taking creatine cause hair loss?
Only one RCT has linked creatine supplementation with an increase in DHT.[1] This study was done in 20 healthy young male rugby players, randomized into two groups: one group took a placebo, while the other supplemented with creatine monohydrate by taking a loading dose (25 g/day) for 7 days, then a maintenance dose (5 g/day) for 14 days. Changes in testosterone were not significantly different between the two groups, but DHT was significantly increased at day 7 (by 0.44 ng/mL above baseline, so 56.1%) and day 21 (by 0.12 ng/mL above baseline, so 40.8%) in the creatine group.
A published response to this study inquired mostly about methods but found no statistical faults.[14] Of note is that this study tested its creatine for 25 different potential adulterants, such as stimulants and androgenic steroids.[14] None were detected, ruling out the possibility that changes in DHT were due to illegal contaminants.
To date, this has been the only RCT testing creatine’s effects on DHT. However, a number of studies have tested creatine’s effects on testosterone. Only two RCTs saw a significant increase in testosterone when supplementing with 20 g of creatine per day over 6 days[15] and 7 days.[16] Ten RCTs have found no effect of creatine on testosterone.[17][18][19][1][20][21][22][23][24][25] These RCTs ranged in duration from 6 days to 10 weeks and used creatine monohydrate doses ranging from 3 to 25 g/day. One RCT that used creatine malate also saw no effect on testosterone levels.[26] Importantly, five of these RCTs specifically tested creatine’s effects on free testosterone, the form that gets converted into DHT. All saw no significant increases.[17][20][22][18][24]
Is it possible for creatine to increase DHT without increasing testosterone, as was reported in one study? Actually, yes, in at least two ways. First, creatine could non-significantly increase free testosterone yet significantly increase DHT (i.e., a small increase in free testosterone, the base material of DHT, could lead to a much greater increase in DHT). Second, creatine could be upregulating 5-alpha-reductase, the enzyme that converts free testosterone to DHT. One or both hypotheses could be true. Or neither. The current evidence simply doesn’t allow us to take a stance.
Before we conclude, we need to mention three caveats. First, these studies were all conducted in healthy young males, and all but one in athletes or other trained individuals. Second, in the one study that looked at DHT and noted an increase, DHT stayed within normal range; so even if creatine increases DHT, it still may not cause greater loss of hair than would otherwise occur. Third, and most important: the effect of creatine supplementation on hair loss hasn’t been directly studied, so all we can make are educated guesses.
One RCT implicated that creatine might increase DHT. While this study has not been replicated, many additional RCTs have shown no effect of creatine supplementation on either total- or free-testosterone levels. To this day, there have been no studies investigating creatine and hair loss.
Bottom line
Only one study has examined the creatine-DHT link (and then, only in males) but many others have shown that creatine does not affect testosterone levels, and since DHT is a metabolite of testosterone, there is some doubt that creatine really increases DHT. If it does, though, then yes, it could contribute to hair loss. However, keep in mind that DHT is only one of many factors that contribute to hair loss; an increase in your blood levels of DHT does not guarantee your hair will fall out. To this day, no studies have directly examined creatine’s effects on hair loss.