A Synthol user from Brazil.

Some bodybuilders, particularly at professional level, inject substances such as "site enhancement oil", commonly known as synthol, to mimic the appearance of developed muscle where it may otherwise be disproportionate or lagging. This is known as "fluffing".[33][34] Synthol is 85% oil, 7.5% lidocain, and 7.5% alcohol.[33] It is not restricted, as it is ostensibly sold for topical use only, and many brands are available on the internet.[35] The use of injected oil to enhance muscle appearance had previously been used in the late 19th century before being abandoned due to health risks such as sclerosing lipogranuloma. Its use was revived more recently by bodybuilders.[36][37] Use can cause pulmonary embolisms, nerve damage, infections, stroke,[33] and the formation of oil-filled granulomas, cysts or ulcers in the muscle.[37][38][39] Sesame oil is often used, which can cause allergic reactions such asvasculitis.[40] An aesthetic issue is drooping of muscle under gravity.[35]

Synthol aftermath (slightly graphic) http://www.liveleak.com/view?i=977_1306477349