Aesthetic Medicine

How long does botulinum toxin last — and when should you repeat it?

It is one of the questions we hear most in consultations. The short answer: on average 3 to 4 months for expression lines. The full answer depends on the area, the dose and each person.

Helder Moreira · 19 October 2026 · 2 min de leitura

In short

A simple timeline

From treatment to gradual return^1,3

2–5 days

Onset

Movement starts to soften.

14 days

Full effect

Time for the follow-up appointment.

3–4 months

Gradual return

Expression returns little by little.

After that

Decide

Repeat, space out or stop — together with your doctor.

What makes it last longer (or shorter)

Factors that affect how long it lasts^1,2

Treated area

Stronger or more used muscles tend to recover sooner.

Dose

Tailored to each muscle: very low doses last less.

Metabolism

It varies from person to person; very active people may notice a shorter effect.

Regularity

With regular treatments, the habit of contracting may lessen.

For safety, treatments should not be repeated at intervals shorter than those recommended in the summary of product characteristics — as a rule, never before about 3 months⁵. Rather than a fixed schedule, the best interval is the one that keeps the result natural for you.

Myths and facts

✕ Myth

“The more often, the higher the dose needed.”

✓ Fact

That is not the rule. The dose is adjusted to the muscle and the desired result at each visit².

✕ Myth

“If I stop, I’ll have more lines.”

✓ Fact

No. The effect wears off gradually and the face returns to how it was².

The duration given is an average: it varies from person to person and cannot be guaranteed. Botulinum toxin is a prescription-only medicine, given after an assessment consultation⁵.

At FACELAB

How we can help.

Botulinum toxin

Forehead, frown lines, crow’s feet and other uses, with a 15-day follow-up included.

Skinboosters

Hydration and skin quality, as a complement.

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.

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

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.
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.
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.
Lowe NJ, Glaser DA, Eadie N, Daggett S, Kowalski JW, Lai PY. Botulinum toxin type A in the treatment of primary axillary hyperhidrosis: a 52-week multicenter double-blind, randomized, placebo-controlled study of efficacy and safety. J Am Acad Dermatol. 2007;56(4):604–611.
INFARMED, I.P. Resumo das Características do Medicamento (RCM) das toxinas botulínicas tipo A autorizadas em Portugal. Base de dados INFOMED.

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