The Side Effects of Synthol: What You Need to Know
Bodybuilding has always carried a culture of pushing physical limits — heavier lifts, stricter diets, and aesthetic goals that often demand years of discipline. But in recent decades, shortcuts have emerged that attempt to bypass the natural growth process. One of the most controversial of these is Synthol, a site enhancement oil (SEO) injected directly into muscles to create the illusion of greater size and fullness.
While Synthol might create an immediate visual impact, the risks it carries are severe and often permanent. The glossy photos of massive, balloon-like biceps that have circulated online are a testament to both the allure and the dangers of this substance. In this article, we’ll break down what Synthol is, how it’s used, and most importantly, the serious side effects that accompany it.
What Is Synthol?
Synthol is not an anabolic steroid or a performance enhancer. Instead, it’s a cosmetic oil that bodybuilders sometimes inject into targeted muscle groups to increase their size instantly. The formula is typically composed of:
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85% oil (often medium-chain triglyceride oil)
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7.5% lidocaine (a painkiller)
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7.5% alcohol (used as a sterilizing agent)
When injected, the oil fills the muscle space and causes the area to swell, giving the impression of bulk and definition without an increase in actual muscle fibers. It does not increase strength, endurance, or performance — only appearance.
Why Do People Use Synthol?
The appeal of Synthol comes from its quick results. Building significant muscle mass naturally requires years of consistent training, dieting, and sometimes the use of anabolic steroids. Synthol, by contrast, can produce visually larger muscles in days.
For some, it’s a way to fix weak points — for example, if a bodybuilder’s biceps lag behind their triceps, they may be tempted to inject Synthol to create symmetry. For others, it becomes a form of body dysmorphia, leading to excessive injections and grotesque proportions that look unnatural and distorted.
But while the cosmetic appeal might seem attractive in the short term, the side effects can be devastating.
Short-Term Side Effects of Synthol
Even within days or weeks of injection, users can face serious complications:
1. Pain and Discomfort
Because Synthol involves injecting large volumes of oil into muscle tissue, localized pain is common. Lidocaine is included to numb the area, but discomfort often returns once the anesthetic wears off.
2. Swelling and Inflammation
The body recognizes the injected oil as a foreign substance. This can trigger an immune response, leading to redness, swelling, and heat at the injection site.
3. Infections
Any time a needle pierces the skin, infection risk exists — especially if injections are done in non-sterile environments. Infections can range from minor abscesses to life-threatening sepsis.
4. Nerve Damage
Poor injection technique or excessive volumes can compress or damage nerves, leading to numbness, tingling, or even partial paralysis of the affected limb.
Long-Term Side Effects of Synthol
The long-term consequences are even more severe and often irreversible.
1. Muscle Fibrosis and Scarring
Instead of integrating into the body, Synthol oil sits in the muscle tissue, where it can harden over time. This causes fibrosis (thick, stiff scar tissue) and permanent damage to muscle function.
2. Loss of Real Muscle Function
As scar tissue replaces healthy muscle fibers, strength and flexibility decline. Ironically, many Synthol users end up weaker despite looking bigger.
3. Disfigurement
Overuse of Synthol often leads to unnatural, lumpy, and swollen-looking muscles that are easily recognizable. Instead of symmetry and proportion, the result is distorted and cartoonish — far from the aesthetic many bodybuilders seek.
