There have been many instances in which muscle-enhancement supplements have been found to contain ingredients not disclosed on the label, such as steroids and stimulants These may explain an increased risk of testicular cancer among men who have reported using muscle-building supplements. Compared to men who never used these supplements, the risk of testicular cancer was found to be 65% higher among those who had, 121% higher if used before age 25, 156% higher if used for more 36 months or longer, and 177% higher if two or more of these supplements had been used.
Be careful of terms like complex or proprietary blend they often do not disclose the actual amount of creatine (or other ingredients) promised in the product. Instead, look for products that list the amount of creatine from creatine monohydrate or another form of creatine. Also be sure to check the suggested serving sizes -- they can be very different from one product to another. Ranging, from less than 250 milligrams to over 20 grams (20,000 mg). Find a product that will provide the dose you want at the lowest cost.
Dosing regimens are designed to increase the levels of creatine in muscle tissue. The standard practice is to start with a "loading" dose of 15 to 20 grams of creatine per day for 5 to 14 days, followed by a maintenance dose of 2 to 5 grams of creatine per day. On this dosing regimen, the maximum creatine storage should occur within 2 to 4 weeks. However, some studies have shown benefit using a constant dose (such as 5 grams daily) rather than a larger loading dose.
(Pline, Ann Pharmacother 2005), (Vahedi, J Neurol Neurosurg Psychiatr 2000),
(Kammer, Pharmacotherapy 2005).
There have been many instances in which muscle-enhancement supplements have been found to contain ingredients not disclosed on the label, like steroids and stimulants. These may explain an increased risk of testicular cancer. Men who have reported using muscle-building supplements. Compared to men who never used these supplements, the risk of testicular cancer was found to be 65% higher among those who had, 121% higher if used before age 25, 156% higher if used for more 36 months or longer, and 177% higher if two or more of these supplements had been used Source: (Li, Brit J of Cancer 2015).
Creatine is generally considered safe when taken in appropriate amounts, but it may cause muscle cramping, diarrhea, and dehydration in some people. There is little known about potential long-term effects of creatine, but there is concern over the potential impact of long-term use at high doses (20 grams/day) on the kidneys and cardiovascular system. Creatine supplements may be dangerous for people with existing kidney disease. In healthy individuals, creatine does not substantially increase blood plasma levels of creatinine and is unlikely to affect estimates of creatinine clearance (a common measure of kidney function) Source: (Pline, Ann Pharmacother 2005). There is concern that creatine should not be used with ephedra and caffeine but this is based on a single report of ischemic stroke in an athlete who was taking this combination Source: (Vahedi, J Neurol Neurosurg Psychiatr 2000). There is also concern that creatine might cause heart arrhythmias based on a report of atrial fibrillation associated with creatine use in a healthy 30-year old man Source: (Kammer, Pharmacotherapy 2005). Creatine can cause weight gain due to water retention.
Be careful of terms like complex or proprietary blend as they often do not disclose the actual amount of creatine (or other ingredients) promised in the product. Instead, look for products that clearly list the amount of creatine from creatine monohydrate or another form of creatine. Also be sure to check the suggested serving sizes -- they can be very different across products, ranging, for example, from less than 250 milligrams to over 20 grams (20,000 mg). Find a product that will provide the dose you want at the lowest cost.
Creatine is thought by some researchers to be harmful to the kidneys. You might be one of the lucky ones who have that problem. It also does affect how the body uses water, requiring that you drink more water than you would need otherwise. There's also no known dosage for it and no good studies on any long-term side effects mostly because most people who take it aren't taking it under medical treatment. Since you can't patent naturally occurring substances, it's hard to get the money together to do really good studies on supplements, and creatine isn't something people have been taking for hundreds of years -- it's a recent pharmaceutical product isolated from food after research showed it might help athletes. The main thing is, any time you take a new supplement and you get unwanted side effects, stop taking the supplement. If the side effects go away, it just isn't the right supplement for you, or you were taking too high a dose for you. Since there's no necessity for you to take it, don't take it.