“Gear” is bodybuilding slang for anabolic steroids and other performance-enhancing drugs. If you’ve seen the term in a forum, YouTube comment, or gym conversation, it’s almost always referring to injectable or oral steroids, though it can sometimes extend to related compounds like peptides. The word exists because people prefer not to say “steroids” openly, especially online where content can be flagged or removed.
What Counts as Gear
The core of what bodybuilders call gear is anabolic-androgenic steroids (AAS). These are synthetic versions of testosterone, the hormone that drives muscle growth in men and, to a lesser degree, in women. The most commonly used compounds include testosterone itself, trenbolone, nandrolone, stanozolol, oxandrolone, oxymetholone, methandrostenolone, and boldenone. Some of these are taken by injection, others as pills.
The term sometimes stretches to include other performance-enhancing substances that aren’t technically steroids: growth hormone, peptides that stimulate growth hormone release, insulin, and newer compounds like SARMs (selective androgen receptor modulators). But when someone says “he’s on gear,” they almost always mean anabolic steroids specifically.
How Steroids Build Muscle
Anabolic steroids work through multiple pathways at once, which is why their effects on muscle size are so pronounced compared to anything available over the counter.
The primary mechanism is straightforward: the steroid enters a muscle cell, binds to androgen receptors, and travels to the nucleus where it switches on genes responsible for building new protein. This ramps up muscle protein synthesis, the process your body uses to repair and grow muscle fibers after training. At the same time, steroids activate satellite cells, which are essentially stem cells that sit on the outside of muscle fibers and donate new material when the fiber needs to grow. More satellite cells active means more raw building material for the muscle.
Steroids also work through a faster, secondary route. Within minutes of entering the bloodstream, they trigger signaling cascades inside cells that further accelerate protein production. One key pathway they activate is the same one your body uses to sense nutrients and decide whether to build or break down tissue. By flipping that switch toward “build,” steroids tilt your entire metabolism in favor of growth.
There’s a third angle that often gets overlooked: steroids are anti-catabolic. They block cortisol, the stress hormone that breaks down muscle tissue. Intense training produces a lot of cortisol, which is part of why natural lifters need careful recovery. By dampening that breakdown signal, steroids shift the balance so that more protein is built than destroyed. The net result is faster recovery, more frequent productive training sessions, and significantly more muscle growth than training alone can produce.
Cycles, Stacks, and Cruising
Gear users don’t typically take steroids continuously and indefinitely, at least not in theory. The community has developed its own vocabulary for how substances are used.
A cycle is a defined period of steroid use, usually lasting 6 to 16 weeks, followed by a similar period off. The idea is to give the body time to recover between periods of use, though the degree to which recovery actually happens varies widely.
Stacking means combining multiple compounds in the same cycle. A user might pair an injectable testosterone base with an oral steroid and a third compound, each chosen for slightly different effects on size, strength, or appearance.
Blasting and cruising is a newer approach where users never fully come off. They “blast” at higher doses for 6 to 12 weeks, then drop to a low “cruise” dose (often just testosterone at a level mimicking natural production) before starting the next blast. This avoids the hormonal crash that comes with stopping entirely, but it also means the body never gets a true break.
Post-Cycle Recovery
When you flood your body with synthetic testosterone, your brain detects the excess and shuts down its own production. The pituitary gland stops sending the hormones (LH and FSH) that tell the testes to make testosterone. After a cycle ends, the body can take weeks or months to restart this process on its own, and in some cases it never fully recovers.
To speed things up, users run what’s called post-cycle therapy (PCT). This typically involves drugs that stimulate the pituitary gland to resume signaling. A common PCT protocol lasts about four weeks. The goal is to restore natural testosterone levels as quickly as possible and hold onto the muscle gained during the cycle. Without PCT, users often experience fatigue, depression, loss of libido, and rapid muscle loss as their hormone levels crater.
Estrogen-Related Side Effects
Testosterone naturally converts into estrogen through an enzyme called aromatase. When steroid doses are high, estrogen levels can spike. In men, excess estrogen causes gynecomastia (breast tissue growth), water retention, and bloating. These are among the most visible and dreaded side effects in bodybuilding circles.
To prevent this, many users take aromatase inhibitors alongside their steroids. These drugs block the conversion of testosterone to estrogen, keeping levels in check. Managing estrogen is considered a routine part of running a cycle, not an afterthought, and getting it wrong in either direction (too much estrogen or too little) causes its own set of problems.
Health Risks
The cardiovascular system takes the hardest hit. Steroid use consistently lowers HDL (“good”) cholesterol and raises LDL (“bad”) cholesterol, a combination that accelerates plaque buildup in arteries. Over time, AAS use is linked to left ventricular hypertrophy, where the heart’s main pumping chamber thickens and stiffens. This can progress to impaired heart function, abnormal heart rhythms, and in severe cases, heart failure. Arterial blood clots and pulmonary embolism are also reported.
The liver faces particular stress from oral steroids, which must pass through it before reaching the bloodstream. Elevated liver enzymes are a reliable marker of this damage. In one documented case of a bodybuilder using AAS, liver enzyme levels were roughly 50 to 70 percent above the normal upper limit.
Hormonal disruption extends beyond testosterone. Prolonged use suppresses LH and FSH so severely that fertility can be compromised for months or years after stopping. Hematocrit (the concentration of red blood cells) tends to rise, thickening the blood and increasing stroke risk. These changes are why experienced users monitor bloodwork regularly, checking lipid panels, liver enzymes, hormone levels, and hematocrit to catch problems early.
Legal Status
In the United States, anabolic steroids are classified as Schedule III controlled substances under the Controlled Substances Act. This puts them in the same category as ketamine and certain codeine products: substances with recognized medical uses but a moderate potential for dependence. Possessing them without a prescription is a federal crime, and distributing them carries heavier penalties.
Because steroids require a prescription, most recreational users obtain them through underground labs or international sources. This introduces a separate layer of risk: products may be contaminated, underdosed, overdosed, or mislabeled entirely. There is no quality control in the black market, and what’s on the label may not match what’s in the vial.
Laws vary by country. In the UK, for example, personal possession is legal but supply is not. In Canada and Australia, steroids are also controlled substances. The legal landscape shapes how openly the topic is discussed and how users access their supply.