Thickened fluids

Last updated: Oct 2026

Back to Eating, drinking and swallowing

Background

Thickened fluids are an intervention for adults and children with difficulties swallowing fluids. In this context, thickened fluids refer to any liquid or drink that is taken orally. Thickened fluids may be naturally occurring or artificially thickened by commercial or non-commercial products.

The RCSLT has developed a position statement, paper, and resources to support dysphagia practitioners to understand the potential benefits and potential burdens associated with thickened fluids to support the practitioner to review their current practice. The position paper is not a systematic review of the literature but provides an overview of the current discussions around using or not using thickened fluids. It is important that each practitioner is aware of the current evidence base within their clinical specialism and decisions around thickened fluids are based on the principles of patient-centred care.

Speech and language therapists (SLTs) should approach this information through a model of evidence-based practice (EBP). SLTs are encouraged to reflect on current practice, base clinical decisions around the needs and preferences of each individual and be aware of the evidence base within their specific clinical area. SLTs should be aware of, and take into account, the position paper and associated documents and then exercise their own professional judgement and carry out research of the latest evidence-base when making clinical decisions.

Recommendations in the position paper advise that service users should not be prescribed thickener for fluids without a detailed drinking and swallowing assessment by a dysphagia trained practitioner. As one of the lead professions for eating, drinking and swallowing difficulties we would promote the vital role of SLTs to achieve this. As a profession which is under increasing pressure due to workforce vacancies and waiting lists, we would encourage commissioners to adequately fund services to achieve this recommendation with consideration of service models, such as rapid response services, which have the potential to be a more effective model of care.

RCSLT position statement and paper

In March 2023, we published our statement on the use of thickened fluids which was aimed at all dysphagia practitioners.

This was followed up with a position paper in January 2024, alongside a summary for SLTs and a summary for non-SLT clinicians as well as other resources which can be found in the resources section. All references are held within the position statement or position paper.

You can also find out more about how we develop our guidance.

Update on use of thickener in dysphagia management

RCSLT has worked closely with members in relation to the use of thickener in dysphagia management for a number of years. We produced a position statement and paper and have also engaged with large scale national research projects e.g. INGEST (dIscontinuing or continuiNG thickEned fluidS Trial).

We were made aware of a number of concerns related to the efficacy of thickener products, as the thickness was found to be variable based on a number of contributory factors. This included temperature of the drink, length of time mixed and left to stand, type of drink (e.g. milk, coffee, orange juice) and particular product manufacturer.

Following the concerns raised, RCSLT are working with two manufacturers to ask for further testing of the products, alongside more guidance and resources to support and improve the overall quality of the products. This work remains ongoing and we will provide updates in relation to specific projects as they progress.

The advice from RCSLT and Nutricia (one of the manufacturers) at present is that:

SLTs should make person-centred recommendations in line with the IDDSI framework, taking account of the service user’s usual drinks and preferences where relevant. Recommendations should focus on achieving the required IDDSI level safely and reliably, rather than specifying a dosage for a particular thickener product. Where the required IDDSI level cannot be achieved safely, reliably, or acceptably, alternative options should be discussed with the service user and/or their proxy.

If you have any queries about this work, please contact info@rcslt.org.

RCSLT resources

To support the position statement and paper we have developed the following resources:

Related RCSLT guidance:

Other resources