The creatine kinase system appears to be detectable in endothelial cells.[314][315] Under basal conditions, creatine itself is expressed at around 2.85+/-0.62μM[316] (three-fold higher than HUVEC cells[314]). When incubating the medium with 0.5mM creatine, endothelial cells can take up creatine via the creatine transporter (SLC6A8) and increase both creatine (almost doubling) and phosphocreatine (nearly 2.5-fold) concentrations.[316]

Earlier during your workout, you might have thought you were starting to see some muscle definition. "Called transient hypertrophy, or a muscle pump, this physiological phenomenon occurs when blood rushes to your muscles to supply them with workout-powering fuel and even jump-start the recovery process," explains certified strength and conditioning specialist Samuel Simpson, co-owner and vice president of B-Fit Training Studio in Miami. He notes that this muscle pump often starts mid-workout and subsides within a few hours after leaving the gym. And as the muscle pump deflates, it's easy to lose determination.
Creatine ethyl ester is more a pronutrient for creatinine rather than creatine,[74] and was originally created in an attempt to bypass the creatine transporter. It is currently being studied for its potential as a treatment for situations in which there is a lack of creatine transporters (alongside cyclocreatine as another possible example).[77] Its efficacy may rely on intravenous administration, however.
Creatine, through its ability to act as an energy reserve, attenuates neuron death induced by the MPTP toxin that can produce Parkinson’s disease-like effects in research animals,[235] reduces glutamate-induced excitotoxicity,[236] attenuates rotenone-induced toxicity,[120] L-DOPA induced dyskinesia,[237] 3-nitropropinoic acid,[238] and preserves growth rate of neurons during exposure to corticosteroids (like cortisol), which can reduce neuron growth rates.[239] Interestingly, the energetic effect also applies to Alzheimer’s disease, during which creatine phosphate per se attenuates pathogenesis in vitro, yet creatine per se did not.[240]

Other areas of research include therapeutic uses of creatine to help patients with muscle wasting caused by disease states such as muscular dystrophy and amyotrophic lateral sclerosis (ALS). Small-scale preliminary studies show some gains in strength may be possible for these patients, which could improve their quality of life. One study of 81 patients with various neurologic diseases found that giving 10 g/day of creatine for five days, followed by 5 grams for another week, increases their muscle strength by about 10% [20]. Large-scale studies should be done before recommendations are made to such patients.
Many athletes follow a "loading" protocol of around 25 grams a day for five days, but this isn't essential. But as Ciaran Fairman notes in the article "Do I Need to Load With Creatine," you can also get the same benefits with around 5 grams a day, potentially with none of the mild side effects of the loading protocol, which include stomach pain and water weight gain. The catch is that you have to take it consistently. Don't skip it!

Lyoo, I. K., Yoon, S., Kim, T. S., Hwang, J., Kim, J. E., Won, W., Bae, S., & Renshaw, P. F. (2012, September). A randomized, double-blind placebo-controlled trial of oral creatine monohydrate augmentation for enhanced response to a selective serotonin reuptake inhibitor in women with major depressive disorder. American Journal of Psychiatry. 169(9):937-45. Retrieved from

Creatine is marketed as "nature's muscle builder" and "the most legitimate sports supplement around." Professional and amateur athletes alike are gobbling up this alleged ergogenic aid, hoping to increase their strength and performance. Creatine supplementation is claimed to increase muscle power by playing a role in the transfer of energy to help the muscle contract. Supplement labels state that "creatine is converted to phosphocreatine, which is important for short energy bursts such as sprinting and weight lifting" and that "depletion of phosphocreatine can result in muscle fatigue and fading muscle power." Claims are also made that supplementation increases muscle body mass.
Product reviews – Since the effectiveness of products varies based on a wide number of factors, one of the best things to do is read creatine product reviews. The best rated creatine products will have consistently good reviews, meaning a lot of people use that product and would recommend it. However – remember to take reviews with a grain of salt, as there’s a lot of ignorance and misinformation out there.
The NitroSurge pre-workout supplement by Jacked Factory aims to get you pumped and focused before a gym session. Besides L-Citrulline, this supplement also contains performance-enhancing betaine anhydrous and beta alanine. It also contains L-theanine which has shown to inhibit nerve cell damage in one study.  For energy-boosting benefits, the NitroSurge is also equipped with caffeine and AstraGin for energy metabolism. Before you buy, consider if you fall under the following circumstances in which this pre-workout would be beneficial to you:
Don’t take sets to the point of failure—where you absolutely can’t perform another rep. You should never get to where you’re turning purple and screaming like you’re getting interviewed by “Mean” Gene Okerlund before WrestleMania. Most of the time, you want to end your sets two reps before total failure. Not sure when that is? The moment your form breaks down, or you’re pretty sure it’s going to break down, end the set.
How to Take It: Take your gainer at any time of day as your objective is to reach overall calorie intake goals. Ideally, instead of using them as a meal substitute, you’ll use your gainer as a snack between high-calorie, healthy, balanced meals. If you plan on taking protein powder for muscle growth in addition to gainers, make sure you add up all of your dietary protein intakes to make sure it’s worth the investment of taking both. You might be able to skip the plain protein powders.
Creatine is a hydrophilic polar molecule that consists of a negatively charged carboxyl group and a positively charged functional group [64]. The hydrophilic nature of creatine limits its bioavailability [65]. In an attempt to increase creatines bioavailability creatine has been esterified to reduce the hydrophilicity; this product is known as creatine ethyl ester. Manufacturers of creatine ethyl ester promote their product as being able to by-pass the creatine transporter due to improved sarcolemmal permeability toward creatine [65]. Spillane et al [65] analyzed the effects of a 5 days loading protocol (0.30 g/kg lean mass) followed by a 42 days maintenance phase (0.075 g/kg lean mass) of CM or ethyl ester both combined with a resistance training program in 30 novice males with no previous resistance training experience. The results of this study [65] showed that ethyl ester was not as effective as CM to enhance serum and muscle creatine stores. Furthermore creatine ethyl ester offered no additional benefit for improving body composition, muscle mass, strength, and power. This research did not support the claims of the creatine ethyl ester manufacturers.