The essential oil of Melaleuca alternifolia, related to clove, eucalyptus and myrtle. All the essential oils from this family have antiseptic properties. Aromatherapists attribute powerful immune stimulant properties to tea tree oil and recommend its use in the bath at the first sign of a cold or the flu. Vaginal douches with a few drops of tea tree oil in warm water are used to treat thrush.

Tempeh

A fermented soya product which originated in the far east and has a firm texture, suitable for slicing and dicing. Tempeh is often used as a meat substitute by vegetarians, and in macrobiotic cookery.

Testosterone

The major male sex hormone (androgen) produced by the male testes. Small amounts are also produced by the ovaries in women, and are subsequently converted to oestrogen. Testosterone is required for sperm production, and for the development of male characteristics, and promotes sex drive in both sexes. In men, testosterone can be converted into another form known as dihydrotestosterone. Increased amounts of dihydrotestosterone have been associated with abnormal prostate gland enlargement, a problem common in middle-aged and elderly men.

Tetracycline

A broad spectrum antibiotic - one which is capable of destroying a wide variety of micro-organisms. When prescribed for lengthy periods for problems such as acne, or to prevent infections in susceptible individuals, there is a very real danger of serious depletion of the beneficial intestinal flora and the development of dysbiosis. Although antibiotics are popularly believed to be harmless drugs, this is not always the case. Tetracycline, for instance, can cause damage to the liver and kidneys.

Theobromine (see Methylxanthines)

Theophylline (see Methylxanthines)