By LIV Clinic · Medically reviewed by Dr. Narathai Vichienkalayarut, M.D. · Published October 16, 2026

One adds lip; the other only reveals the lip you already have. For genuinely thin lips, that distinction decides everything.

Botox lip flip or lip filler for thin lips? For genuinely thin lips, filler is usually the better answer, because a lip flip adds no volume — it relaxes the muscle around the mouth so the upper lip rolls slightly outward, revealing a little more pink. A flip suits a subtle change or a thin upper lip with a gummy smile; filler suits actual volume loss.

What each treatment actually does

The lip flip

A few units of botulinum toxin are placed in the muscle just above the upper lip. As the Cleveland Clinic explains of the mechanism, the muscle’s contraction is temporarily reduced — so the lip stops curling inward and rolls very slightly outward.

Lip filler

Hyaluronic acid gel is placed in the lip to add volume and shape. The Cleveland Clinic describes fillers as adding volume to areas that have lost it, which is a genuinely different intervention from relaxing a muscle.

Why thin lips usually need filler

A flip reveals, it does not add

If there is very little pink lip to begin with, rolling it outward reveals very little. The change is measured in a millimetre or two of visible lip.

When a flip is enough

A flip can work well where the lip is reasonably full but curls under when you smile, or where a gummy smile is the main concern.

Side-by-side comparison

Typical ranges only; your own result and duration will vary.

Trade-offs worth knowing before you choose

Honest considerations on both sides:

• A lip flip can make it briefly harder to whistle, sip through a straw or pronounce some sounds
• A flip is subtle enough that some people feel it was not worth the visit
• Filler can look overdone if too much is placed in a small lip
• Filler carries the usual injectable risks of swelling, bruising and lumps
• Filler is reversible, which makes a conservative first treatment lower-stakes
• Neither is permanent, so both require repeat treatment to maintain

Combining the two

Why doctors sometimes do both

Filler supplies volume while a small flip stops the upper lip disappearing when you smile. Combined conservatively, the two address different mechanics.

Sequencing

Most doctors treat one first and review before adding the second, so the effect of each is clear rather than guessed at.

Getting a natural lip result

Start small

For first-time filler, a conservative amount with a review is far safer than aiming for the final result in one appointment.

Proportion over volume

A natural lip result depends on balance between upper and lower lip and on your own facial proportions rather than millilitres placed.

Step-by-step: choosing and preparing

How to work through the decision:

1. Photograph your lips at rest and smiling, from the front and in profile.
2. Decide whether your concern is volume, shape, or the lip curling under when you smile.
3. Book a consultation and ask which mechanism your doctor sees as the main issue.
4. If volume is the problem, discuss a conservative first filler treatment rather than a full syringe.
5. Avoid alcohol and blood-thinning supplements for 24–48 hours beforehand, where appropriate.
6. Expect swelling for two to three days after filler; plan around events accordingly.
7. Review at two weeks before deciding whether to add more or combine treatments.

Lip treatments at LIV Clinic

Doctor-led and conservative

At LIV Clinic on Koh Samui and Koh Phangan, Dr. Narathai assesses lip proportion and movement before recommending a flip, filler or both — and will say when a flip would be too subtle to be worth it.

Read next

Compare our dermal filler and Botox and wrinkle pages, or book a consultation.

Frequently asked questions

Safety and consultation

Lip enhancement is a prescription medical treatment and, like any injectable, carries some risk — common temporary effects can include redness, swelling, bruising, mild headache or a short-lived heaviness, and less common reactions such as temporary eyelid or brow droop 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.