No. It’s not easy for everyone to get the recommended amount of protein in their diets through good eating habits alone. Others may not have clinically low testosterone, but still benefit from boosting their levels to improve their muscle building capacity. You can fix these common problems through muscle building supplements. These easy to take pills and powders can also help you boost your performance at the gym which will, in turn, spur your body’s muscle building and recovery response.
A typical creatine supplementation protocol consists of a loading phase of 20 g CM/d or 0.3 g CM/kg/d split into 4 daily intakes of 5 g each, followed by a maintenance phase of 3-5 g CM/d or 0.03 g CM/kg/d for the duration of the supplementation period [5]. Other supplementation protocols are also used such as a daily single dose of around 3 – 6 g or between 0.03 to 0.1 g/kg/d [15,55] however this method takes longer (between 21 to 28 days) to produce ergogenic effects [5]. Sale et al [56] found that a moderate protocol consisting of 20 g CM taken in 1g doses (evenly ingested at 30-min intervals) for 5 days resulted in reduced urinary creatine and methylamine excretion, leading to an estimated increase in whole body retention of creatine (+13%) when compared with a typical loading supplementation protocol of 4 x 5 g/d during 5 days (evenly ingested at 3 hour intervals). This enhancement in creatine retention would lead to a significantly higher weight gain when people follow a moderate protocol ingestion of several doses of small amounts of CM evenly spread along the day.
Endogenous serum or plasma creatine concentrations in healthy adults are normally in a range of 2–12 mg/L. A single 5 g (5000 mg) oral dose in healthy adults results in a peak plasma creatine level of approximately 120 mg/L at 1–2 hours post-ingestion. Creatine has a fairly short elimination half-life, averaging just less than 3 hours, so to maintain an elevated plasma level it would be necessary to take small oral doses every 3–6 hours throughout the day. After the "loading dose" period (1–2 weeks, 12–24 g a day), it is no longer necessary to maintain a consistently high serum level of creatine. As with most supplements, each person has their own genetic "preset" amount of creatine they can hold. The rest is eliminated as waste. A typical post-loading dose is 2–5 g daily.[52][53][54]
It doesn’t get more natural than getting a good night’s sleep. Research published in the Journal of the American Medical Association showed that lack of sleep can greatly reduce a healthy young man’s testosterone levels. That effect is clear after only one week of reduced sleep. Testosterone levels were particularly low between 2 and 10 p.m. on sleep-restricted days. Study participants also reported a decreased sense of wellbeing as their blood testosterone levels dropped.
Creatine is stored in the body in the form of creatine and as creatine phosphate, otherwise known as phosphocreatine, which is the creatine molecule bound to a phosphate group.[39] Creatine phosphate is thought to maintain the ATP/ADP ratio by acting as a high-energy phosphate reservoir.[40] The more ATP a muscle has relative to ADP, the higher its contractility is, and thus its potential strength output in vivo.[41][42] This pro-energetic mechanism also affects nearly all body systems, not just skeletal muscle. [39] During periods of rest and anabolism, creatine can gain a phosphate group through the creatine-kinase enzyme pathway, up to a cellular concentration of 30uM[24] to be later used for quick ATP resupply, when needed.[43][44] 
Because the distribution of muscle strength is unique to each there is no short answer to this question. A personal trainer simply cannot tell all his/her customers to perform a bench press using 100 pounds because it will be too difficult for some and too easy for others. Rather the idea here is to use the right amount of weight that will make you successful in accomplishing the objective set previously (muscle power, strength or endurance).

Researchers described the study as one of the first to examine how strength training can reduce the risk of cardiovascular disease, separate from the effects of aerobic activity like running or long walks. The point: for those who are not meeting recommended guidelines for aerobic activity—perhaps because they lack the time—bursts of weight training can be enough.

Some other cytokines and hormones may increase the receptor activity. These include growth hormone (GH) which acts upon the growth hormone receptor (GHR)[166][167] to stimulate c-Src[168][169] which directly increases the activity of the CrT via phosphorylation. This is known to occur with the 55kDa version of c-Src but not the 70kDa version and requires CD59 alongside c-Src.[170]
Both testosterone and 5α-DHT are metabolized mainly in the liver.[1][155] Approximately 50% of testosterone is metabolized via conjugation into testosterone glucuronide and to a lesser extent testosterone sulfate by glucuronosyltransferases and sulfotransferases, respectively.[1] An additional 40% of testosterone is metabolized in equal proportions into the 17-ketosteroids androsterone and etiocholanolone via the combined actions of 5α- and 5β-reductases, 3α-hydroxysteroid dehydrogenase, and 17β-HSD, in that order.[1][155][156] Androsterone and etiocholanolone are then glucuronidated and to a lesser extent sulfated similarly to testosterone.[1][155] The conjugates of testosterone and its hepatic metabolites are released from the liver into circulation and excreted in the urine and bile.[1][155][156] Only a small fraction (2%) of testosterone is excreted unchanged in the urine.[155]
Maughan RJ, King DS, Lea T. Dietary supplements. J Sports Sci. 2004 Jan;22(1):95-113.Kreider RB. Dietary supplements and the promotion of muscle growth with resistance exercise. Sports Med. 1999 Feb;27(2):97-110.Kerksick CM, Rasmussen CJ, Lancaster SL, et al. The effects of protein and amino acid supplementation on performance and training adaptations during ten weeks of resistance training. J Strength Cond Res. 2006 Aug;20(3):643-53.Update of Cochrane Database Syst Rev. 2001;(1):CD002946. Glucosamine therapy for treating osteoarthritis. Cochrane Database Syst Rev. 2005 Apr 18;(2):CD002946.AIS Sports Nutrition - AIS Sports Supplement Program 2007.
Brain injury. Early research shows that taking creatine by mouth daily for 7 days increases the ability to exercise by increasing lung function in people with a spinal cord injury. However, other research shows that creatine does not improve wrist muscle or hand function. Early research also shows that taking creatine by mouth daily for 6 months reduces amnesia following a traumatic brain injury in children.
Studies that use a dosage range typical of creatine supplementation (in the range of 5g a day following an acute loading period) note increases to total body water of 6.2% (3.74lbs) over 9 weeks and[608] 1.1kg over 42 days.[609] Interestingly, some studies comparing creatine paired with training against training itself fail to find a significant difference in percentage of water gained (which is inherently to activity) with standard oral doses of creatine[609][607][610] (although low dose creatine supplementation of 0.03g/kg or 2.3g daily doesn’t appear to increase water retention[611]) despite more overall water weight being gained, due to an equal gain of dry mass in muscles. One study has quantified the percentage increase in mass of muscle cells to be 55% water, suggesting the two groups are fairly equal.[609]
The majority of your workouts should be comprised of compound exercises. Common examples include squats, deadlifts, lunges, bench presses, rows, pull-ups, lat pull-downs, overhead presses, and so on. Isolation exercises should definitely also be a part of your program, just a smaller part in comparison. Common examples include bicep curls, tricep extensions, chest flies, lateral raises, leg curls, leg extensions, calf raises, and so on.
Other side effects include increased risk of heart problems in older men with poor mobility, according to a 2009 study at Boston Medical Center. A 2017 study published in JAMA found that treatments increase coronary artery plaque volume. Additionally, the Food and Drug Administration (FDA) requires manufactures to include a notice on the labeling that states taking testosterone treatments can lead to possible increased risk of heart attacks and strokes. The FDA recommends that patients using testosterone should seek medical attention right away if they have these symptoms:
Medicines used for treating depression are called antidepressants and may be categorized into several classes. Some of these drugs include tricyclic antidepressants such as Nortriptyline and Imipramine, Selective serotonin reuptake inhibitors (SSRIs) including Fluoxetine, Citalopram, and Sertraline, and Selective Norepinephrine Reuptake Inhibitors (SNRIs) including Venlafaxine and Duloxetine. These drugs, generally, act by increasing the amounts of chemical substances that stimulate the brain. Each class of antidepressants has a different safety profile and side effects, so, ensure you consult your doctor for a prescription and dosage recommendations.
Han:SPRD‐cy rats (human polycystic kidney disease model[514][515]) have pre-existing renal damage, which is accelerated upon ingestion of creatine supplementation at 0.3% of the diet for five days and 0.03-0.05% for the next 35 days (equivalent to human loading and maintenance).[516] During this particular disease state, renal water content and size progressively increases.[514][515] Since creatine supplementation furthered the increase by an additional 2.1%, it was thought that this property of creatine explained the 23% increased cyst scores seen relative to control.[516]
This amino acid is actually produced by your body and so is considered a non-essential amino acid. However, in addition to taking it in supplement form, beta-alanine is also found in protein-heavy foods like meat and fish (9). This amino acid has been linked to performance enhancement outcomes, especially for weightlifters. Studies show increased performance when taking this supplement.
The Branched-Chain Amino Acids, BCAAs for short, are leucine, valine and isoleucine.  Essentially, its a form of protein powder for muscle gain or other uses. These essential amino acids are not made by the body but are found in foods such as meats, dairy products and legumes. In medicine, BCAAs are used for a number of conditions, however, for many uses, further research is necessary to determine whether or not treatment is effective.

But muscle can’t turn into fat, just like mud can’t turn into gold. If you quit lifting, your muscles mass will decrease over time because there’s no training to stimulate your body to keep it. And your body-fat level will increase if you don’t start eating less (since you burn less). The obvious solution when you stop lifting is to also stop eating so much.
After all, if you’re doing more reps in a set, the weight would obviously be lighter and the intensity level lower. If you’re doing fewer reps in a set, the weight is obviously heavier and the intensity is higher. In addition, how close you come to reaching failure – aka the point in a set when you are unable to complete a rep – also plays a role here.
One case study on a subject with a methylentetrahydrofolate reductase (MTHFR) 677TT homozygote, a relatively common genetic mutation known as “mild MTHFR deficiency,” which causes mild homocysteinemia,[310] has seen benefits due to creatine supplementation where homocysteine was approximately halved (49% reduction) while CT heterozygotes and CC homozygotes (n=9) were unaffected.[311] Additionally, one rat study suggested a possible role for creatine in reducing homocysteine levels in a model of high uric acid levels (model for end stage renal disease[312]) but this was not replicated when investigated in humans.[313]
Low testosterone levels can cause mood disturbances, increased body fat, loss of muscle tone, inadequate erections and poor sexual performance, osteoporosis, difficulty with concentration, memory loss and sleep difficulties. Current research suggests that this effect occurs in only a minority (about 2%) of ageing men. However, there is a lot of research currently in progress to find out more about the effects of testosterone in older men and also whether the use of testosterone replacement therapy would have any benefits.
The other interesting thing about the study: men’s testosterone levels were lowest in March (at the end of winter) and highest in August (at the end of summer). Sunlight affects your vitamin D production, so you have seasonal dips and peaks. Get a blood test to check your levels, and if you’re low, take a high-quality vitamin D3 supplement. If you’re going to take D3, take vitamin K2 and vitamin A with it. The three work in sync, so you want them all to be balanced. Here are my dosage recommendations.
Testosterone is included in the World Health Organization's list of essential medicines, which are the most important medications needed in a basic health system.[111] It is available as a generic medication.[10] The price depends on the form of testosterone used.[112] It can be administered as a cream or transdermal patch that is applied to the skin, by injection into a muscle, as a tablet that is placed in the cheek, or by ingestion.[10]
Beta-alanine is a naturally occurring non-essential amino acid that comes into the body through foods that are rich in protein. The performance-enhancing aspect of beta-alanine (BA) is due to its ability to increase intra-muscular levels of carnosine. Increasing beta-alanine through supplementation may raise carnosine levels by over 60 percent in as quickly as four weeks.[6]
Start with the barbell on the supports of a power rack at about shoulder height. Grab the bar overhand and raise your elbows until your upper arms are parallel to the floor. Now lift the bar off the rack, letting it roll toward your fingers-this is where it should rest throughout the exercise (as long as you keep your elbows raised, you won’t have trouble balancing the bar) [1]. Squat as low as you can [2], and then drive with your legs to return to the starting position. That’s one rep.

Even human studies can be misinterpreted or manipulated. A few years ago a then-esoteric trace mineral called boron was found to increase testosterone, but only in older women, as it turned out. When boron was tested in young men engaged in weight training, it proved worthless for increasing testosterone. That doesn't mean boron is useless; it helps the body use the minerals calcium and magnesium, and it appears to increase mental alertness.
The gluteus maximus is the largest and most superficial of the three gluteal muscles. It makes up a large portion of the shape and appearance of the hips. It is a narrow and thick fleshy mass of a quadrilateral shape, and forms the prominence of the nates. The gluteus medius is a broad, thick, radiating muscle, situated on the outer surface of the pelvis. It lies profound to the gluteus maximus and its posterior third is covered by the gluteus maximus, its anterior two-thirds by the gluteal aponeurosis, which separates it from the superficial fascia and integument. The gluteus minimus is the smallest of the three gluteal muscles and is situated immediately beneath the gluteus medius.
The important role of nutrition in building muscle and losing fat means bodybuilders may consume a wide variety of dietary supplements.[41] Various products are used in an attempt to augment muscle size, increase the rate of fat loss, improve joint health, increase natural testosterone production, enhance training performance and prevent potential nutrient deficiencies.
Testosterone begins with cholesterol. In fact, every single sex hormone you make you synthesize from cholesterol – that’s one reason a “heart healthy” low-fat, low-cholesterol diet limits your performance. Fat and cholesterol don’t make you fat. They give your body the building blocks to create abundant testosterone and other sex hormones, which actually makes you lose weight and build muscle, especially if your current testosterone levels are low [1].

Pellets. Your doctor will place the testosterone pellets under the skin of your upper hip or buttocks. Your doctor will give a shot of local anesthesia to numb your skin, then make a small cut and place the pellets inside the fatty tissues underneath your skin. This medication dissolves slowly and is released over about 3-6 months, depending on the number of pellets. 
This claim has not been demonstrated at this time, and a recent comparative study of buffered creatine against basic creatine monohydrate found no significant differences between the two in 36 resistance trained individuals, in regard to the effects or the accumulation of creatine in muscle tissue.[71] There also were no significant differences in the amount of adverse side-effects reported.
Fatherhood decreases testosterone levels in men, suggesting that the emotions and behavior tied to decreased testosterone promote paternal care. In humans and other species that utilize allomaternal care, paternal investment in offspring is beneficial to said offspring's survival because it allows the parental dyad to raise multiple children simultaneously. This increases the reproductive fitness of the parents, because their offspring are more likely to survive and reproduce. Paternal care increases offspring survival due to increased access to higher quality food and reduced physical and immunological threats.[60] This is particularly beneficial for humans since offspring are dependent on parents for extended periods of time and mothers have relatively short inter-birth intervals.[61] While extent of paternal care varies between cultures, higher investment in direct child care has been seen to be correlated with lower average testosterone levels[62] as well as temporary fluctuations. For instance, fluctuation in testosterone levels when a child is in distress has been found to be indicative of fathering styles. If a father's testosterone levels decrease in response to hearing their baby cry, it is an indication of empathizing with the baby. This is associated with increased nurturing behavior and better outcomes for the infant[63].
It raised the question about performance-enhancing drugs. Their murky role in bodybuilding has long shrouded the sport. A 2013 documentary on Heath and Mr. Olympia called “Generation Iron” (a sort of bookend piece to 1977’s “Pumping Iron,” which launched Schwarzenegger and others to fame) called the topic “taboo.” It then insinuated that, of course, bodybuilders competing in top-level contests like Mr. Olympia use steroids.

Eat 1.5–3 grams of carbs per pound of your body weight. As with fat, this amount can vary greatly, depending on your personal needs and preferences, so consider these numbers only a starting point. If you’re very skinny and feel that you handle carbs well (i.e. you can eat a lot of them without getting fat), go ahead and eat according to the higher end of the spectrum. The same applies if you’re desperate to gain weight—you should increase your carb intake. If you’re prone to weight gain or feel lethargic on higher carbs, you should eat fewer of them. Again, see our keto guide for more details and options.
Testosterone is the primary male sex hormone and an anabolic steroid. In male humans, testosterone plays a key role in the development of male reproductive tissues such as testes and prostate, as well as promoting secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair.[2] In addition, testosterone is involved in health and well-being,[3] and the prevention of osteoporosis.[4] Insufficient levels of testosterone in men may lead to abnormalities including frailty and bone loss.
Great! Start with strength training 🙂 When you’re overweight, my guess is that you want to be preserving the muscle you have while losing the majority of your weight through fat. With strength training, your overall weight loss may seem slower, but you will lose inches faster. Strength training increases your metabolism; as long as you’re still eating in a deficit, you’ll lose weight.
According to the abstract, in the stratified analyses by forms of aerobic exercise, weekly resistance exercise of 1 time or 1-59 minutes was associated with lower risks of total cardiovascular events and cardiovascular disease, regardless of meeting the aerobic exercise guidelines. The analysis showed that resistance training reduced the risk of cardiovascular events in 2 ways: training had a direct association with cardiovascular risk, and resistance training indirectly lowered cardiovascular risk by decreasing body mass index.
Yes, you can pack on size while only doing bodyweight exercises – I did it while traveling the world – and gymnasts train mostly with bodyweight movements. However, this can feel like playing Halo on Legendary difficulty. It can be done, but damn it can be challenging – especially for lower body movements. If your sole goal is to get bigger as fast as possible, access to a barbell for squats and deadlift is almost a requirement.
The winner of the annual IFBB Mr. Olympia contest is generally recognized as the world's top male professional bodybuilder. The winner of the Women's Physique portion of the competition is widely regarded as the world's top female professional bodybuilder. The title is currently held by Juliana Malacarne, who has won every year since 2014. Since 1950, the NABBA Universe Championships have been considered the top amateur bodybuilding contests, with notable winners such as Reg Park, Lee Priest, Steve Reeves, and Arnold Schwarzenegger. Winners generally go on to become professional athletes.
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:

Creatine, the amino acid, naturally helps your body produce more adenosine triphosphate, or ATP, a small molecule that’s actually your body's primary energy source. But research shows that your body is only capable of storing enough ATP for 8 to 10 seconds of high-intensity exercise — and after that, it needs to produce new ATP for you to continue. (9)
Like other steroid hormones, testosterone is derived from cholesterol (see figure).[128] The first step in the biosynthesis involves the oxidative cleavage of the side-chain of cholesterol by cholesterol side-chain cleavage enzyme (P450scc, CYP11A1), a mitochondrial cytochrome P450 oxidase with the loss of six carbon atoms to give pregnenolone. In the next step, two additional carbon atoms are removed by the CYP17A1 (17α-hydroxylase/17,20-lyase) enzyme in the endoplasmic reticulum to yield a variety of C19 steroids.[129] In addition, the 3β-hydroxyl group is oxidized by 3β-hydroxysteroid dehydrogenase to produce androstenedione. In the final and rate limiting step, the C17 keto group androstenedione is reduced by 17β-hydroxysteroid dehydrogenase to yield testosterone.

In humans, studies that investigate links between serotonin and creatine supplementation find that 21 trained males, given creatine via 22.8g creatine monohydrate (20g creatine equivalent) with 35g glucose, relative to a placebo of 160g glucose, was found to reduce the perception of fatigue in hot endurance training, possibly secondary to serotonergic modulation, specifically attentuating the increase of serotonin seen with exercise (normally seen to hinder exercise capacity in the heat[233]) while possibly increasing dopaminergic activity (conversely seen to benefit activity in the heat[234]).[155]

Multivitamin supplements may help you reach the recommended daily intakes for vitamins and minerals if you have a less than ideal diet, travel impairs your diet, or strenuous exercise increases requirements. I consider a multivitamin good insurance in these circumstances against possible deficiencies. Choose a reputable brand. You should choose a good all-around supplement with a balanced formula.
I know this goes against the recommendations you often see in stereotypical bodybuilding routines (i.e. the ones that involve having a single “chest day” or “arm day” or “shoulder day” once a week), but that’s just one of the many reasons why those types of routines suck for us natural, genetically-average people, and work best for steroid users with great genetics.
A loading phase of 10g creatine monohydrate for two weeks and 4g for the final week in subjects with MELAS (Mitochondrial Encephalomyopathy Lactic Acidosis and Stroke-like episodes) has been noted to increase physical strength relative to baseline, although the poor VO2 max seen in these subjects was not affected.[549] A case study exists in which a patient with a relatively novel mutation in their mitochondrial function (affecting cytochrome B) experienced benefits from creatine at 10g daily.[550] Researchers examining another case of MELAS found both cognitive and physical benefits with 5g creatine supplementation,[551] while four controlled case studies of 100-200mg/kg daily in children with myopathies found improved muscular endurance (30-57%) and muscular power (8-17%) after 100-200mg/kg daily for at least three months.[552]
Related to exercise and fitness, BCAAs are taken to help reduce muscle breakdown, which is why they may be known as muscle building supplements. Leucine, in particular, is known for playing an important role in muscle protein synthesis, which can help with muscle gain and maintenance. Some also claim that BCAAs can enhance performance, although many studies also refute this claim.
If you want to take creatine as a supplement for bigger and stronger muscles, then the standard protocol is to have a “loading period” where you significantly increase your creatine intake for a few days or weeks. “This can prime your muscles to increase the amount of creatine that they ‘hold,’” explains Bates. “During the loading period, you generally take 5 g of creatine four times per day. After the loading period, you decrease the amount of creatine you take to a ‘maintenance’ level of 3 to 5 g per day.” (That’s also the recommendation from the International Society of Sports Nutrition.) (5)
You don't need to design a fresh plan every three weeks. Scaling up weight and modifying reps are obviously both important for progression, but playing with different set styles will shock your body and keep things interesting. Remember, bodybuilding isn't meant to feel like a chore. Below, we explain eight different types of sets to help you build muscle more efficiently during bodybuilding training.
When it comes to training, I prefer to stick with the basics. People think they need 10 different exercises to fashion a fine pair of cheeks, but that's not what it takes. When it comes to toning your glutes, you only need two things: drive and dedication—and I mean real dedication. You must train your glutes hard and diligently to get a great response. If you stop every time it gets difficult or whenever it burns, you're not going to get anywhere.
In addition to the proper amount of sleep, do not overdo your training regimen. While you might be tempted to think that "more is better," in fact the opposite is true. You can reach a point known as "over-training", in which you'll lose the ability to "pump" (engorge the muscles with oxygen-rich blood) your muscles, and this can even lead to muscle wasting—exactly the opposite of what you are trying to achieve. Here are some symptoms to be aware of if you think you may be falling into the over-training zone:
Intensive weight training causes micro-tears to the muscles being trained; this is generally known as microtrauma. These micro-tears in the muscle contribute to the soreness felt after exercise, called delayed onset muscle soreness (DOMS). It is the repair of these micro-traumas that results in muscle growth. Normally, this soreness becomes most apparent a day or two after a workout. However, as muscles become adapted to the exercises, soreness tends to decrease.[22]

Professional-athlete-turned-biohacker Maximilian Gotzler gave a speech about boosting testosterone at the 2015 Bulletproof Conference. He started by leading the room through the Haka, a Maori war dance that New Zealand’s pro rugby team has made popular. The Pasadena Conference Center trembled as over 100 people shouted and stomped in unison. It was awesome.
Prison food isn’t as bad as people think. Prisoners often get three meals a day. Meals need to meet a certain amount of calories. You don’t need that much protein to build muscle, but prisoners can buy protein powder (and also extra food like oatmeal). Prisoners aren’t underfed in most western countries. The diet may not be optimal, but it’s sufficient to build muscle.

You've figured out the exercises you should be doing, but what about the number of sets and repetitions? Your decision should be based on your goals. The American College of Sports Medicine recommends 4 to 6 reps for strength and hypertrophy, 8 to 12 reps for muscular strength and 10 to 15 reps for muscular endurance. They also recommend at least one set of each exercise to fatigue although you'll find that most people perform about 2 to 3 sets of each exercise. In general:
However, caffeine does not negate the benefits of creatine loading when not coingested, but just taken before exercise in the same dosage.[593] This result indicates that loading creatine without caffeine on a daily basis, but saving caffeine for select workouts, may be an effective strategy, as creatine does not adversely affect caffeine’s ergogenic effects[593][594] and may enhance creatine’s effectiveness in anaerobic exertion if the two compounds are alternated.[595]

^ Jump up to: a b Lazaridis I, Charalampopoulos I, Alexaki VI, Avlonitis N, Pediaditakis I, Efstathopoulos P, Calogeropoulou T, Castanas E, Gravanis A (2011). "Neurosteroid dehydroepiandrosterone interacts with nerve growth factor (NGF) receptors, preventing neuronal apoptosis". PLoS Biol. 9 (4): e1001051. doi:10.1371/journal.pbio.1001051. PMC 3082517. PMID 21541365.