This article is based solely on my professional opinion and experience, but I have taken into account experimental, epidemiological and anecdotal evidence. The list is in no particular order (except for the first two, which, I feel, are the most useful), and, indeed, not all listed are appropriate for every bodybuilder, but all listed have their uses for some individuals. Most of the others not listed here, I feel, are a waste of money (though I keep a slightly open mind, as there are new developments). You do not need supplements to build a great physique, but they are an extremely useful and effective way of improving your gains.

Engineered Nutrition Meal Replacement Powders (MRPs)
These are 'complete' nutrition containing high protein, moderate carbohydrate, essential fatty acids and all vitamins and minerals. They are an invaluable aid to the bodybuilder as they can be used to substitute one or more of the many meals he/she has to consume in a day; or can be used to complement a meal. MRPs should be made up with water only.

I believe MRPs started quite a few years ago with MetRx, which is still a great product, but since then, many other companies have developed their own, and improved on the original idea. Some now include pre- and probiotics (see separate article) and many anutrients (substances found in food which have no nutritional value per se but have been found to have health benefits).

Other examples are ProMR (Chemical Nutrition Products) and Myoplex Plus (EAS). Most come in portion sachets, but some are available in tubs. The problem is, sachets make up to a large volume which can be hard to consume in one go, and they are very expensive.

A must for the keen bodybuilder.

Quality Protein Powders
A few years ago, a new system of filtration identified ion-exchange whey protein as a top quality protein source. Before then, protein powders were based on cheap, poor quality soya protein, or egg white protein (which mixes poorly).

The debate on whey continues: There is no doubt as to its high biological value, similar amino acid profile to that of human muscle tissue, and that it is digested, absorbed and taken up by muscles quickly. Some people feel it passes too quickly through our gut, so not all is available for absorption. Other quality protein powders are combination ones, containing two or more sources of protein. These often include whey, but other sources as well, so there is a more staged digestion of the protein.

All quality whey and combination protein powders are invaluable to the bodybuilder, as it is often impractical to eat the amount of high protein food required for optimal gains. Mix with water, and consume in between or as a compliment to meals

Weight Gain Formulas
Weight gain powders will always have their place in the bodybuilding market. I do not mean the ridiculously high calorie crash weight gain formulas full of simple carbohydrate and fats; but the moderately high calorie, high protein formulas such as N-Large and Pro-Mass. Typically these are 600 kcal, 50g protein per serving, and can be mixed with water or skimmed milk.

Weight gain formulas are not necessary for every bodybuilder, but very useful for the skinny newcomer who struggles to eat enough food to put on quality weight. Also useful for the off season more-advanced bodybuilder with a fast metabolism and busy lifestyle to add a few more quality calories.

Mulidextrose Powders
Multidextrose is a synthetic polysaccharide which our body treats like starch, i.e. a complex carbohydrate. Multidextrose is used by a range of sports people to help meet the high-energy demands of intense exercise, especially by tri-athletes. In bodybuilding it is invaluable for the lean hard gainer who struggles to eat enough carbohydrate each day. Just adding the powder to drinks can increase intake by 6-800kcals a day. Multidextrose powders are cheap, and useful for bulking up on.

Amino Acid Capsules
Not essential, but can be useful for improving protein quality. Avoid the tablets, as these have binders and are less well absorbed; capsules are more easily digested.

I am a big believer in mixing two or more sources of protein at each meal. Remember that we are bodybuilders, and although the protein sources we eat may be 'complete', we have higher demands for each amino acid than 'normal' people do. If it's impractical to mix proteins, take a few amino acid capsules to help ensure quality protein at each meal. Not necessary with whey or whole egg sources, as these are already high quality protein sources.

Amino acids are not essential, but could be useful for more advanced bodybuilders to take with food.

My main criticism of these has to be price; is there really a need for them to be so expensive? Supplement bars are very useful for the busy bodybuilder, especially if he/she is bulking up.

Pre-Workout Drinks
Energy drinks come in a vast array of different concoctions, some just sugar-based and some containing a range of stimulants like caffeine, guarana and ephedra. Again very expensive, but nice tasting and many feel they need them to train after a hard day at work. I will not recommend any particular types, I'll leave that for you to decide which you prefer; but avoid the high sugar (glucose) ones which are full of calories, as these can have a rebound effect on your energy levels and, in fact, cause sluggishness. To avoid stomach cramps, sip them before and during workouts, don't gulp!

GABA
Gamma-aminobutyric acid (GABA) is used by some with mixed reports of effectiveness. It became popular after the gamma-hydroxybutyrate (GH scare, which was used as a growth hormone releaser and subsequently a recreational drug. GABA is a natural substance found in the same chemical pathway as GHB.

Taken before bed it (supposedly) gives deeper quality sleep, hence more GH release and you feel better the next day. Some people like to use it pre-workout and claim it gives them a 'buzz' during training; I have tried this and it made me feel worse. I don't know about the increase in GH release, as I can find no clinical studies, but it does improve sleep quality, and it has been said you can get 8 hours worth of sleep in 6 hours - useful for the busy-lifestyle bodybuilder.

Watch out for its unpleasant side effect of shortness of breath about 10 minutes after ingestion which lasts about 5 minutes. This can be scary if unexpected.

GABA has its place on the supplement rack and isn't too expensive. Don't use it too often, so a tub will last months.

Creatine Monohydrate
Probably the most scientifically researched supplement ever, results of which are conclusive in that creatine does help improve performance. Here's the science in brief: ATP is used for energy, by being broken down to ADP and AMP. Creatine Phosphate (CP) is found in muscle cells and replenishes ADP/AMP to ATP; hence more ATP is available for energy. It has been found that muscles can store far more CP than is possible to obtain from food (creatine is found in meat), so by supplementing with creatine monohydrate you can maximise these stores. More CP stored in muscle also draws water into muscle and makes it fuller and stronger.

Not only does creatine allow you to have more energy (through the above process) to help lift heavier weights, train harder and at higher intensity, but it also has other benefits to the bodybuilder. It has been demonstrated that creatine may also promote muscle growth by stimulating protein synthesis in two ways. Firstly, from the increased work you are able to do as a result of the above actions. But also, creatine's other principle function is as a cell volumiser, the more CP that is stored in muscle, the more water is drawn in. This aids ability to work, enhances the muscle 'pump' and helps to trigger protein synthesis, minimise protein breakdown and increase glycogen synthesis. If a muscle is then trained properly, this could lead to enhanced muscle growth.

Creatine formulas
You will see a number of formulas each marketed as being 'the best'! To sum it up - only use creatine monohydrate powder. Creatine phosphate, creatine citrate and creatine serum are useless. Some are marketed with special transport mechanisms, but these are expensive. Stick to the basics.

How to use creatine
You will hear a number of theories as to the best way of supplementing with creatine, some say take with a carbohydrate load; some say take with a hot beverage so it dissolves and is absorbed more easily; some advocate a loading and maintenance phase; some say only a maintenance dose of 5g a day and loading is a waste. My justification for having a loading phase is down to its side effect of nausea and using a continual 5g a day for weeks on end can be a lot to stomach. Though a loading phase does mean more creatine per day initially, this is only for a few days and enables a maintenance dose of merely 2g. Some argue that having a loading phase is just a way of companies selling more but, if you use my regimen below, you will actually require less.

It is also recommended to take creatine with simple carbohydrates. Pre-formulated creatine + carbs concoctions are available, but these are very expensive and contain excessive amounts of sugars, it is far cheaper and better to add your own carbs.

My conclusion, studying all data, it appears the following may be the optimal way of using creatine:

Take creatine monohydrate powder in a hot beverage with sugar (or a sugary cordial with hot water) with fruit with a loading and maintenance phase as follows: Loading phase: 10g per day as 2 x 5g for 5 days; 5g per day for 5 days; 3g per day for 7 days.
Maintenance phase: 2g per day for 5 weeks.

This may be followed by a period off, or back on the loading phase.

Some 'experts' claim that creatine shouldn't be taken with caffeine, like tea or coffee. They say that caffeine inhibits optimal absorption of creatine due to its effect on carbohydrate take up by muscle, and there is sub-optimal hydration of muscle too. There is no evidence to substantiate these claims, and I really fail to see that caffeine with creatine is a problem, as long as you continue to drink plenty of fluid.

Creatine is not the be-all-and-end-all of supplements and is certainly not fundamental to your nutrition regimen, though it is worth giving it a try to see for yourself. There are side effects namely nausea, especially on the loading phase, and quite intense muscle cramps, which can lead to injuries if you are not cautious whilst training. You MUST drink plenty of fluid whilst using creatine.

Glutamine
Again loads of research here, but with very mixed results. Glutamine is also used clinically in the intensive care setting to aid wound healing, and it is the amino acid preferred as a source of energy for intestinal muscle cells; but its use here also remains controversial. Bodybuilders use it for the same reasons, in that we stress our bodies intensely. Scientific evidence points to glutamine being of no use in sports, but anecdotal reports have shown benefits.

If you do feel glutamine is worth it, take it at least half an hour away from other protein sources, as other amino acids will compete for receptor uptake. Take it with carbohydrate, e.g. in fruit juice. Glutamine has its place for the more advanced bodybuilder, in aiding recovery.