Initial effects of the treatment start after a period of 48-72 hours, but it can take up to 14 days to see the full effect. The effects of the treatment usually last between 3–5 months, this will vary from person to person. Deep lines will be softened and may take several treatments until the optimum result is achieved. Too frequent or excessive dosing of botulinum toxin may increase the risk of antibodies in the blood, which may lead to failure of treatment. With this in mind, and the recommended guidelines, botulinum toxin treatments are carried out after 12 weeks. You should have further treatment when the muscle activity returns, but before the lines and wrinkles have had a chance to re-establish. The injections are virtually painless and may cause a minor stinging discomfort. As the needles are very small, the risk of bleeding or bruising is minimal. You can resume normal activities straight afterwards.