Taking high doses of creatine might harm the kidneys. Some medications can also harm the kidneys. Taking creatine with medications that can harm the kidneys might increase the chance of kidney damage.

Some of these medications that can harm the kidneys include cyclosporine (Neoral, Sandimmune); aminoglycosides including amikacin (Amikin), gentamicin (Garamycin, Gentak, others), and tobramycin (Nebcin, others); nonsteroidal anti-inflammatory drugs (NSAIDs) including ibuprofen (Advil, Motrin, Nuprin, others), indomethacin (Indocin), naproxen (Aleve, Anaprox, Naprelan, Naprosyn), piroxicam (Feldene); and numerous others.

So, for example, with the moves above you'd do 15 squats followed by 15 push-ups. Take a little breather then repeat that two more times. Then you move on to your walking lunges and lat pull-downs (and repeat those three times total, too). You can really do anywhere from eight reps to 15 (and even just two sets, if you don't have time for three), but "it’s not a bad idea for beginners to start with a 15-rep range to get comfortable with the exercises," says Davis. And while there's some debate over whether three sets of an exercise is really best, "it’s a great beginner model," says Davis. Don't overcomplicate things when you're just getting started.
Nephrotoxic drugs. Because taking high doses of creatine might harm your kidneys, there is concern about combining creatine with drugs that might damage the kidneys (nephrotoxic drugs). Potentially nephrotoxic drugs include nonsteroidal anti-inflammatory drug (NSAIDs) such as ibuprofen (Advil, Motrin IB, others) and naproxen sodium (Aleve, others), cyclosporine (Neoral, Sandimmune) and others.

Many other important bodybuilders in the early history of bodybuilding prior to 1930 include: Earle Liederman (writer of some of bodybuilding's earliest books), Zishe Breitbart, Georg Hackenschmidt, Emy Nkemena, George F. Jowett, Finn Hateral (a pioneer in the art of posing), Frank Saldo, Monte Saldo, William Bankier, Launceston Elliot, Sig Klein, Sgt. Alfred Moss, Joe Nordquist, Lionel Strongfort ("Strongfortism"),[6] Gustav Frištenský, Ralph Parcaut (a champion wrestler who also authored an early book on "physical culture"), and Alan P. Mead (who became an impressive muscle champion despite the fact that he lost a leg in World War I). Actor Francis X. Bushman, who was a disciple of Sandow, started his career as a bodybuilder and sculptor's model before beginning his famous silent movie career.
Gordon, P. H., Cheung, Y. K., Levin, B., Andrews, H., Doorish, C., Macarthur, R. B., Montes, J., Bednarz, K., Florence, J., Rowin, J., Boylan, K., Mozaffar, T., Tandan, R., Mitsumoto, H., Kelvin, E. A., Chapin, J., Bedlack, R., Rivner, M., McCluskey, L. F., Pestronk, A., Graves, M., Sorenson, E. J., Barohn, R. J., Belsh, J. M., Lou, J. S., Levine, T., Saperstein, D., Miller, R. G., and Scelsa, S. N. A novel, efficient, randomized selection trial comparing combinations of drug therapy for ALS. Amyotroph.Lateral.Scler. 2008;9:212-222. View abstract.
HMB supplementation is claimed to build muscle size and strength and promote fat loss in conjunction with a strength program. Studies of HMB have shown some benefit to strength athletes in building muscle bulk but the benefits are relatively small and the cost of HMB is high. The effective dose seems to be 3 grams/day divided into 1 gram three times a day. Probably not worth taking. Beta-alanine is the new guy on the block and has not been evaluated sufficiently in my view. It may provide some advantage in high-intensity sports like weight training but it’s much too early to know that it does. Some early studies are flawed. Save your money or try creatine instead.
In people with COPD given either glucose placebo (40.7g) or creatine supplementation (5.7g creatine with 35g glucose) thrice daily for two weeks followed by a single dose for ten weeks, supplementation was associated with improvements in muscular strength and endurance, but not cardiovascular exercise potential.[579] A later trial of larger power using a loading phase of 22g creatine with a maintenance phase of 3.76g during rehabilitative exercise failed to replicate the improvements in skeletal muscle performance despite increased body weight seen with creatine,[580] and the failure to improve cardiovascular performance during aerobic exercise seen in both aforementioned studies has been replicated elsewhere after eight weeks supplementation, during which muscular performance was, again, unaffected.[581]
Perform the two workouts (Day 1 and 2) once each per week, resting at least a day between each. Perform the exercises marked with letters as a group. Do one set of A, rest, then one set of B, rest (note that some groups have an exercise “C”), and repeat until all sets are complete. Then go on to the next group. Perform three sets of 8–10 reps for each exercise. After a month, you’ll see how rewarding just a months in the gym can be.

In otherwise healthy adults subject to leg immobilization for two weeks while taking 20g creatine daily during immobilization and then 5g daily during eight weeks of rehabilitation, it was noted that the creatine group failed to reduce atrophy during the immobilization (10% reduction in cross sectional area and 22-25% reduction in force output) despite preventing a decrease in phosphocreatine, yet experienced a significantly enhanced rate of regrowth and power recovery.[358] A similarly structured and dosed study has also noted greater expression of skeletal muscle, GLUT4 expression, and a 12% increase in muscle phosphocreatine content.[330]
Homocyteine (normal serum range of 5-14µM) is known to adversely affect motor control in genetically susceptible people when their levels exceed 500µM, which is usually associated with genetically induced deficiencies of B12.[360][361] In these particular instances (assessed by rats fed homocysteine to increase serum levels to such a high level[362][363]) it appears that administration of 50mg/kg creatine (injections) to these rats can protect dysfunction in muscle metabolism (pyruvate kinase activity, Krebs cycle intermediates, and muscle cell viability) induced by homocysteine.[363]
One pilot study using 150mg/kg creatine monohydrate for a five day loading phase followed by maintenance (60mg/kg) for the remainder of the five weeks noted that supplementation was associated with fewer muscle symptoms and complaints alongside improved muscular function,[572] yet a later trial trying to replicate the obsevations using 150mg/kg daily for five weeks noted the opposite, that creatine supplementation exacerbated symptoms.[573]