Trapezius botulinum toxin: how many units and how long it lasts

100 units or 200 units?

The trapezius is one of the larger muscles anyone treats with toxin, so the dose scales with how much of that muscle needs relaxing. Barog states the shoulder-line treatment at two levels — a one-hundred-unit dose and a two-hundred-unit dose — because the amount that gives a visible, lasting result depends heavily on how developed and how strong the muscle is.

A lighter, one-hundred-unit level can suit a slighter or less prominent trapezius, or someone wanting a subtle softening instead of a marked change. A fuller, two-hundred-unit level tends to fit a bulky, well-built muscle in someone who carries a lot of tension across the shoulders, where a smaller dose would soften the ridge only briefly. The two are not better or worse — they are matched to the muscle in front of the injector.

Because the trapezius does real work in daily movement, the aim is to relax the bulk that pushes the shoulder line up, not to switch the muscle off. At the consultation the injector judges how large and how powerful your trapezius is, then recommends the dose that balances a clear result against keeping the shoulder functioning normally.

How long the effect holds

Botulinum toxin does not act the instant it is placed. The relaxing effect on the trapezius builds over roughly two to four weeks, so the shoulder line looks progressively slimmer across the first month, not on the day of treatment — a timeline worth planning around if you have an event in mind.

Once it has taken hold, the effect on the shoulder line generally lasts in the region of three to six months before the muscle gradually regains its former activity. That is a general span, not a fixed figure; where you land depends on your own muscle and how quickly your body processes the toxin, which is why the candid answer is a range confirmed by how your own result behaves.

The fade is gradual, not sudden. As the effect wears off, the trapezius slowly rebuilds its bulk and the shoulder line drifts back toward its untreated shape, giving you clear warning before a repeat is worth considering instead of an abrupt loss of the result.

Do repeat sessions need fewer units?

Many people find that with consistent, well-spaced treatment a habitually overactive trapezius becomes less bulky over time, and a muscle that is doing less work can sometimes be maintained on a steadier or slightly lighter dose than the first correction needed. That pattern is common, but it is not a rule you can bank on before it happens.

How the muscle responds is individual. Some people keep a similar dose each session because their trapezius stays strong, while others settle into a lighter maintenance dose once the peak bulk has eased. The injector makes no promise of a falling number; instead they review how your shoulder line looks at each visit and adjust the units to what the muscle actually needs that time.

Spacing matters here too. Letting the previous treatment do its full work before the next session, and not topping up too soon, is what gives the muscle the chance to settle — and that measured cadence is part of why a maintenance plan can sometimes hold on less than the initial dose.

How Barog sets your dose

Barog states the shoulder-line dose at the one-hundred and two-hundred-unit levels on the price board, so at the consultation you can see both doses and understand which suits your muscle, with no vague open pricing to decode. The board supplies the tiers; the injector supplies the recommendation after assessing your trapezius.

Because genuine, sealed toxin is used throughout and written treatment records note the exact product and units placed, any repeat session starts from a clear record — a real advantage when the plan is to fine-tune the dose over time. Bring the detail of any previous toxin treatment to the visit, since it helps the injector judge where to set your units this time.

If your treatment lands on a Busan trip, have the injector walk through both the expected onset over the first weeks and the likely interval before a repeat, so a follow-up can be timed sensibly instead of guessed.