Synthol is a controversial substance often associated with extreme physical aesthetics, particularly within certain subcultures of bodybuilding. The dramatic, rapid changes in muscle size observed after its use have led to the inaccurate assumption that it functions as a highly potent anabolic steroid. Synthol operates through a completely different mechanism than performance-enhancing drugs, providing volume without genuine strength gain. Understanding what Synthol is and how it interacts with the body clarifies the profound risks involved.
Synthol’s Chemical Identity
Synthol is fundamentally a site enhancement oil (SEO) and is definitively not classified as an anabolic androgenic steroid (AAS). Anabolic steroids are synthetic derivatives of the male hormone testosterone, which chemically bind to androgen receptors to stimulate protein synthesis and cellular growth, a process known as hypertrophy. Synthol contains no hormonal compounds and does not engage in chemical signaling pathways to build muscle tissue.
The substance is typically a mixture of three main components: oil, anesthetic, and alcohol. The composition is predominantly an oil base (approximately 85%), often consisting of medium-chain triglycerides (MCT). The remaining volume is usually split between 7.5% lidocaine, a local anesthetic, and 7.5% alcohol, which acts as a thinning agent and sterilizer. This chemical makeup confirms that Synthol is a physical filler, entirely distinct from the hormonal action of a steroid.
Mechanism of Action in Muscle Tissue
The visual effect of increased muscle size created by Synthol is achieved through displacement rather than physiological growth. When the oil is injected deep into a muscle belly, it remains localized, acting like a foreign, permanent implant that immediately increases the volume of the targeted area. The substance is trapped between the muscle fibers, causing the appearance of a larger, fuller muscle contour.
The sequestration of oil initiates a prolonged inflammatory response as the body attempts to deal with the foreign material. Localized swelling and subsequent reaction contribute to the immediate size increase, but the underlying muscle tissue remains unchanged in strength or function. Over time, the body attempts to wall off the injected oil, leading to the formation of scar tissue, or fibrosis, around the oil pockets. This process maintains the artificial volume, not an increase in muscle cell size or number.
Acute and Long-Term Health Consequences
Injecting foreign oil into muscle carries immediate health dangers. One acute risk is a pulmonary oil embolism, which occurs if the oil accidentally enters a blood vessel and travels to the lungs, potentially blocking the pulmonary artery. This vascular occlusion can swiftly lead to respiratory failure, heart attack, or stroke. Furthermore, incorrect injection technique can damage local nerve bundles, resulting in chronic pain, numbness, or even partial paralysis in the affected limb.
The long-term consequences relate to the body’s foreign body reaction and the oil’s permanent presence. Chronic inflammation and the formation of granulomas—nodules of immune cells—are common reactions to the trapped oil. This chronic inflammation leads to extensive muscle fibrosis, resulting in painful and debilitating scarring of the tissue. In severe cases, the disfigurement and muscle necrosis caused by the oil may necessitate extensive surgical intervention to excise the damaged tissue.