By LIV Clinic · Medically reviewed by Dr. Narathai Vichienkalayarut, M.D. · Published July 28, 2026

There is no universal number — your forehead’s dose is written in your own muscle, not a price list.

How many units of Botox do I need for forehead lines? Most people need roughly 10 to 20 units for the forehead itself, though the exact number depends on your muscle strength, line depth and goals — and the forehead is usually treated alongside the frown lines for a balanced result.

The typical range

Forehead lines

The horizontal lines from raising your brows come from the frontalis muscle. Most treatments use roughly 10 to 20 units here; the Cleveland Clinic cites a range of about 10 to 30 units depending on the approach.

Why a range, not a number

Muscle strength varies enormously between people, so the same look can need very different doses — which is why an assessment matters more than a price list.

Why the frown lines matter too

They work together

The frontalis lifts the brows; the frown (glabella) muscles pull them down. Treating the forehead alone can leave the frown unopposed and the brows feeling heavy.

Typical frown dosing

The frown area commonly takes around 20 units, often given across five injection points, which is why forehead and frown are usually planned together.

What changes your dose

Your number depends on:

• How strong your forehead muscle is
• How deep your lines are at rest
• Your brow position and any heaviness
• Whether you want softening or stronger smoothing
• Your sex — men often have stronger muscles and need more
• Whether it is your first treatment or a top-up

Typical units by area

*Illustrative only; your injector confirms the right dose for your anatomy and goals.

Why starting conservative is smart

You can add, not remove

Botox cannot be reversed, so a measured first dose with a two-week review is safer than starting strong — a small top-up can always be added.

Avoiding brow heaviness

Over-treating the forehead is the classic cause of heavy brows or a ‘frozen’ look, which conservative, balanced dosing avoids.

How long the result lasts

The Cleveland Clinic notes the effect is temporary. Most people find forehead results last about three to four months before movement gradually returns and a maintenance visit is due. Longevity varies with dose, muscle strength and metabolism.

Getting your dose right

To get an accurate, personalized dose:

1. Have a consultation so Dr. Narathai can assess your muscle strength and brow position.
2. Discuss whether you want softening or stronger smoothing.
3. Agree whether to treat the frown alongside the forehead.
4. Start conservatively for a first treatment.
5. Review at about two weeks to assess the result.
6. Add a small top-up then if you want more.

Forehead Botox at LIV Clinic Koh Samui

At LIV Clinic, your unit count is decided at consultation by Dr. Narathai based on your muscles and goals — not a fixed package. Explore our Botox and wrinkle treatments, see how Botox is priced on Koh Samui, or book a consultation.

Frequently asked questions

Safety and consultation

Botox is a medical procedure and, like any injectable, carries some risk — common temporary effects can include redness, swelling, bruising or a mild headache, and less common reactions are possible. Results vary from person to person, and no specific outcome can be promised. This article is general information, not medical advice.

At LIV Clinic, every treatment begins with an in-person assessment by Dr. Narathai Vichienkalayarut, M.D., who reviews your skin, medical history and goals before recommending a personalized plan. Book a consultation to find out whether this treatment suits you.