Protein supplements take three main forms - predigested protein, 'free' amino acids,

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and specific individual amino acids.
Suppliers claim that predigested protein and free amino acids are absorbed more quickly by the body. This claim is tenuously based on clinical studies on hospitalised patients fed by tube or drip. Under these extreme circumstances, it has been found that mixtures of individual amino acids or predigested protein are more easily absorbed and used by the body. However, no studies have convincingly demonstrated any benefit for healthy people. Food is a perfectly adequate way to get your amino acids - and cheaper too!

Arginine, ornithine and lysine
These individual amino acids are promoted as 'growth hormone releasers'. Supplement manu-facturers suggest that these amino acids will increase muscle growth while stimulating breakdown of body fat. This is another case of gross distortion of the known facts. Arginine, ornithine and lysine are known to increase levels of human growth hormone when injected into the bloodstream at high doses. Whether there's any effect when these substances are given by mouth is far more controversial. Many researchers have found no effect. A couple of studies which found that ornithine supplements increased growth hormone levels used levels so high that nausea and diarrhoea were unwelcome accompaniments to the hormone boost

If single amino acids are consumed in large quantities, absorption of others may be affected; there is also a risk of toxic effects


Boron compounds
Commonly advertised as testosterone boosters, some manufacturers refer to a study published in 1987 to back up their claims. Anyone actually looking up the study might well be disappointed, as it documents the effects of various minerals on hormone levels in post-menopausal women. Aluminium and magnesium reduced circulating levels of testosterone - boron appeared to return these levels to normal. The researchers did not extrapolate their results to any other group of people. In a more recent study, young male bodybuilders were divided into two groups and given boron or placebo for seven weeks. There was no difference between the groups for plasma testosterone, lean mass or strength

Use of boron supplements may not just be ineffective - there have been reports of increased infertility in parts of the previous Soviet Union, where drinking water contained high concentrations of boron