Aesthetic Medicine

Botulinum toxin: what it is, how it works and when to start.

It is the most performed non-surgical aesthetic procedure in the world4 — and one of the most surrounded by myths. Here is, plainly, what you can (and cannot) expect.

Helder Moreira
Helder Moreira  ·  14 October 2026  ·  3 min de leitura
Rosto de mulher com pele natural e linhas de expressão suaves

In short

How it works

Botulinum toxin type A is a prescription-only medicine that temporarily and locally blocks the signal between nerve and muscle. The treated muscle contracts less, so the skin above it creases less. Over time, lines that were visible at rest also soften3,5.

It works mainly on dynamic lines — those that appear when you frown, smile or raise your eyebrows. It does not add volume or treat sagging: other treatments do that1.

Where it is used1,2

01

Forehead

Horizontal lines when raising the eyebrows.

02

Frown lines

The “11” between the brows that can look tired or cross.

03

Crow's feet

Lines at the corners of the eyes when you smile.

04

Other uses

Teeth grinding, gummy smile, neck bands and excessive sweating — after a medical assessment.

What to expect, day by day

Timeline of the effect2,5

Day 0

Treatment

10–15 minutes with very fine needles. Back to your routine the same day.

2–5 days

Onset

Movement starts to soften.

14 days

Full effect

The ideal time for a review appointment.

3–4 months

Gradual return

The muscle slowly recovers. Repeat treatments maintain the result.

When should you start?

There is no right age. It makes sense when expression lines start to show at rest, or when they bother you. International data show it is most sought after between 35 and 504; many people start with low doses, to soften lines without losing expression. The goal is not to look 20: it is to look rested.

Myths and facts

✕ Myth

“My face will look frozen.”

✓ Fact

The dose is tailored to each muscle. Done well, expressions stay natural1.

✕ Myth

“It’s dangerous — it’s a toxin.”

✓ Fact

Tiny doses of a medicine used in medicine for over 30 years, administered by doctors3.

✕ Myth

“If I stop, lines will get worse.”

✓ Fact

No. The muscle gradually returns to how it was2.

Usual aftercare advice

Do

Avoid for 24 hours

It is not suitable during pregnancy or breastfeeding, with neuromuscular diseases or with an active infection in the area6. That is why every treatment starts with a medical consultation.

A plan made for you.

Every face and every skin is different. Book an assessment: we review your case and design a personalised treatment plan with you, with realistic goals.

Helder Moreira

Written by

Helder Moreira

Physician accredited in Aesthetic Medicine · Portuguese Medical Association (Ordem dos Médicos) — licence no. 55532

Patient information

The procedures and treatments mentioned in this article require a prior individual medical assessment and, in some cases, a medical prescription. Indications, results and their duration vary from person to person and cannot be guaranteed. This article is for information only and does not replace a medical consultation.

For more information contact Facelab, Lda. on +351 961 023 229, by email at geral@facelab.pt, or visit www.facelab.pt.

  • FACELAB Albufeira — Rua do Estádio, Quinta da Bela Vista, Lote 2, 8200-127 Albufeira · ERS Registration Certificate: E172446 · Operating licence: 24619/2024
  • FACELAB Faro — Rua da PSP, n.º 22, 8000-408 Faro · ERS Registration Certificate: E180121 · Operating licence: 26536/2025

References

  1. Carruthers J, Fagien S, Matarasso SL; Botox Consensus Group. Consensus recommendations on the use of botulinum toxin type A in facial aesthetics. Plast Reconstr Surg. 2004;114(6 Suppl):1S–22S.
  2. Sundaram H, Signorini M, Liew S, et al. Global Aesthetics Consensus: Botulinum toxin type A — evidence-based review, emerging concepts, and consensus recommendations for aesthetic use, including updates on complications. Plast Reconstr Surg. 2016;137(3):518e–529e.
  3. Nigam PK, Nigam A. Botulinum toxin. Indian J Dermatol. 2010;55(1):8–14.
  4. International Society of Aesthetic Plastic Surgery (ISAPS). ISAPS International Survey on Aesthetic/Cosmetic Procedures performed in 2023. 2024.
  5. Satriyasa BK. Botulinum toxin (Botox) A for reducing the appearance of facial wrinkles: a literature review of clinical use and pharmacological aspect. Clin Cosmet Investig Dermatol. 2019;12:223–228.
  6. INFARMED, I.P. Resumo das Características do Medicamento (RCM) das toxinas botulínicas tipo A autorizadas para uso estético. Base de dados INFOMED.
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Helder Moreira