How long does Botox last, and why does yours fade sooner?

Where the three-to-four month figure comes from

Botulinum toxin blocks the signal between nerve ending and muscle. The block itself is not undone; instead the nerve grows new terminals around it, and that regrowth takes roughly twelve to sixteen weeks. That is the mechanism behind the three-to-four month figure, and it is why no injector can make a standard dose last a year. Anyone promising six months from one session is either overdosing you or counting the fade-out as effect.

Why yours wears off faster than your friend's

Muscle mass is the biggest single factor: a heavy frontalis or a strong masseter needs more units to reach the same effect and recovers sooner. Regular endurance training and a high metabolic rate shorten duration measurably. First treatments also fade faster than later ones, because untrained muscle is stronger. Men typically need twenty to thirty percent more units than women in the same area for the same result. That is anatomy, not pricing strategy.

What actually improves with repeated treatment

By the second or third cycle the treated muscle has partly weakened from disuse, so the same result needs fewer units and holds a few weeks longer. More importantly the static line, the crease still visible when your face is completely still, starts to soften, because the skin is no longer being folded a thousand times a day. That is the real long-term argument for treating early and lightly rather than late and heavily.

The mistake of chasing it too soon

Two rules protect the result. Review at day fourteen, not day five: the effect is not fully in yet, and topping up early is how eyebrows end up uneven. And leave at least three months between full sessions, because frequent small doses raise the theoretical risk of neutralising antibodies and, in practice, blur where you are in the cycle. If it has faded at ten weeks, the answer is more units next time, not another session now.

The Ones People Actually Ask.