At 21, persistent forehead creases come from one of three sources, and the right approach differs for each. Frontalis overactivity (most common at your age):The frontalis is the muscle that raises your eyebrows. When it works harder than necessary (often unconsciously to compensate for tired eyes, dry contact lenses, or just habit), it creates horizontal forehead lines. Botox or Dysport in small doses softens the muscle activity and lines. What's notable in your case: the asymmetry you mention is often a clue that one side of the frontalis is working harder than the other. Targeted Botox dosing — a slightly different amount on each side — can balance the asymmetry while softening lines on both sides. Compensatory raising for brow ptosis:If your brow position is slightly low (even subtly), your frontalis works overtime to lift the brow throughout the day, creating lines as a side effect. In this case, Botox alone can make the issue worse (brow drops further when frontalis is relaxed). Solution involves addressing the underlying brow position — usually with a small temporal brow lift, even at a young age. Genetic deep lines:Some patients have deeper dermal creases even without significant muscle activity. These respond to microneedling, fractional laser, or carefully placed superficial filler. For the asymmetry specifically:Eyebrow asymmetry at 21 is usually one of two things: Compensatory frontalis activity on one side (Botox fix as above). Underlying skeletal asymmetry of the brow ridge (less common, no easy fix beyond camouflage with makeup or hairline work). What I'd recommend at 21:Start with a careful Botox evaluation by an injector who specifically watches muscle behavior at rest and animation. The injector should observe you naturally for a minute or two — not just look at static photos — to understand which muscles are dominant. Micro-dose Botox (sometimes called baby Botox) is often the right starting dose at your age — minimal units to soften activity without freezing expression. Three months later, reassess and adjust. Avoid heavy doses at first, and avoid procedures targeting the brow ridge until you've seen what Botox alone accomplishes.