Drooling (‘dribbling’ or ‘poor saliva control’) impedes socialization, interpersonal relationships, and integration into school and community life. In adults, it may limit employment options. The loss of self-esteem and the increased amount of personal care required are ongoing problems for both individuals and their carers. In addition, the secretions damage books, clothing, and computer equipment and skin may become excoriated. Despite drooling being a common problem in both children and adults with cerebral palsy and other neurological conditions, none of the available treatment options are totally satisfactory. Behavioural approaches and techniques employed by speech pathologists are often not successful, medication may have undesirable side effects, and surgery may not be effective and is associated with a risk of long-term dental problems unless dental surveillance is optimal.1 The introduction of botulinum toxin injections for drooling has been welcomed as it provides another treatment option for this difficult problem. However, more evaluation is required to determine optimal dosages, frequency of injection, and long-term outcomes, both adverse and beneficial. In addition, the efficacy of botulinum toxin versus other treatments such as medication and surgery needs to be compared. There is an emerging body of literature regarding the use of botulinum toxin for saliva control but few randomized trials are currently available to guide practice. Hence the randomized trial comparing three different doses of botulinum toxin B (BoNT-B) by Basciani et al.2 is a useful addition to the literature. Twenty-seven children were randomized to four groups: a control group, and low (1500MU), medium (3000MU), and high doses (5000MU) of botulinum toxin. The medium dose (3000MU) was found to be the most effective with the low dose being ineffective and the high dose being associated with very significant adverse effects. Two children receiving the high dose developed severe dysphagia and weakness, requiring hospitalisation and nasogastric tube feeding. Adverse effects including dysphagia have been noted even when BoNT-B is given at a distal site.3 Ongoing caution with dosage is required particularly in this group of children who often already have dysphagia, poor oromotor control, and are at risk of aspiration. The finding of an effective dose of 3000MU is similar to that recommended in the recent consensus statement where suggested dosages were based on the available literature and clinical experience.4 The dose for Myobloc (BoNT-B) was 250 to 1000U into the submandibular and 400 to 1000U into the parotid glands. When comparing doses in the literature it is very important to clarify which serotype and which commercial preparation was used. In addition, it is important to differentiate the dose of botulinum toxin per individual salivary gland from the total dose administered per kilogram of body weight. Information to guide the choice of toxin remains limited. The different preparations of BoNT-A and BoNT-B have different effects at the cellular level, different pharmacokinetics, and different adverse event profiles. The diffusion characteristics of the toxin and the dose and dilution used, may have an impact on both the suppression of drooling as well as the risk of dysphagia and aspiration. BoNT-B has a shorter duration of action and has additional systemic autonomic adverse effects suggesting that BoNT-A may be preferable for the management of saliva control.5 However, in one study involving 30 children with cerebral palsy or neurodegenerative disease, BoNT-A and BoNT-B were found to be equally effective with similar side effects.6 More comparative clinical trials of type A and type B botulinum toxins are urgently needed. There has been a recent report of changes suggesting that repeated doses of BoNT-A cause muscle atrophy and loss of contractile tissue in target muscles and also in non-target muscles that are far removed from the injection site.7 Whilst this may represent a significant problem in muscle, saliva gland atrophy could potentially be useful, decreasing the amount of secretions over time. Some shrinkage of the size of the saliva glands following repeated injections has been anecdotally reported. Carefully designed studies, measuring the size of the saliva glands following repeated injections of botulinum toxin, need to be undertaken. There is no shortage of useful studies to be done to improve the management of this distressing problem.