What are the Contraindications for Thickeners?

January 7, 2026 •

2 min read

Thickeners can help manage dysphagia, but their use requires caution because it can cause complications for some patients. An understanding of the limitations and contraindications associated with thickener use is important.

Quick Summary

Thickeners help manage swallowing problems but have risks. Patient age, medical history, thickener type, and medication use must be considered before use. Careful evaluation is required.

Key Points

Necrotizing Enterocolitis Risk: Xanthan gum-based thickeners, like SimplyThick, are contraindicated in premature and young infants due to a serious risk of NEC.
Dehydration and Malnutrition: Reduced oral intake due to poor palatability, altered texture, and early satiety can lead to dehydration and malnutrition, requiring close monitoring.
Compliance is Crucial: Thickeners are ineffective if instructions are not followed, which can be a problem for patients with cognitive impairment, taste aversion, or low motivation.
Underlying Medical Conditions: Patients with a history of aspiration pneumonia, impaired laryngeal sensation, or poor performance status are at higher risk of complications, even with thickeners.
Medication Absorption: Thickeners can interfere with medication dissolution and absorption, necessitating consultation with a pharmacist and close monitoring to ensure drug efficacy.
Starch vs. Gum Differences: Starch-based thickeners are broken down by saliva, which can alter consistency mid-swallow, while gum-based ones are more stable but have specific age contraindications.

Understanding the Role of Thickeners

Thickeners change the consistency of liquids and foods, making them easier to swallow for people with dysphagia. Conditions such as stroke, Parkinson's disease, dementia, and head and neck cancers can lead to swallowing difficulties. While thickeners can reduce the risk of aspirating thin liquids, their use is not without risks. Specific clinical situations and patient factors can make thickeners inappropriate or even dangerous.

Key Contraindications and Associated Risks

High-Risk Patient Populations

Several patient populations are at a higher risk of adverse outcomes from thickener use and may have specific contraindications:

Infants and Premature Babies: Xanthan gum-based thickeners have been linked to an increased risk of necrotizing enterocolitis (NEC) in premature and young infants, a severe intestinal disease. For this reason, the use of certain gum-based thickeners is contraindicated in this population.

Nutritional and Hydration Risks

Thickeners can lead to reduced fluid intake and dehydration. This can be due to poor palatability, early satiety, and potentially reduced access to drinks.

Medication Interactions

Thickeners can interfere with medication absorption. They should not be used to thicken crushed pills or liquid medications without consulting a pharmacist and physician.

Comparison: Starch-Based vs. Gum-Based Thickeners

Understanding the differences between thickener types is crucial for safe selection.


Feature	Starch-Based Thickeners	Gum-Based Thickeners	Consideration for Contraindication
Effect in Saliva	Thinned by salivary amylase.	Stable in saliva.	Consistency changes can increase aspiration risk, particularly with poor oral control.
Consistency Over Time	Continues to thicken after mixing.	Generally stable.	Unpredictable consistency increases risk if not consumed promptly.
Impact on Infants	Use with caution.	Contraindicated in premature and young infants due to NEC risk (e.g., xanthan gum products).	Critical contraindication for young infants with gum-based products.
Palatability	Can be cloudy and grainy.	Better texture and clarity, but can alter taste.	Affects compliance and hydration levels.

The Critical Role of Professional Guidance and Monitoring

Thickener use requires a thorough swallowing assessment by a Speech-Language Pathologist (SLP) and ongoing monitoring. The lowest effective thickness level should be used. Key practices include formal assessment, monitoring of hydration and nutrition, regular reassessment of swallowing function, and maintaining good oral hygiene. Further information is available from professional bodies like the Royal College of Speech and Language Therapists.

Conclusion: A Double-Edged Sword

Thickeners are valuable for dysphagia but present risks. While they can improve swallowing safety for some, they can also cause dehydration, nutritional issues, and medication interactions. Use must be an individualized decision based on professional assessment, with contraindications existing for certain high-risk groups, including premature infants and those with specific medical conditions. Continuous monitoring and reassessment are vital to balance benefits and risks.

Royal College of Speech and Language Therapists: Position paper on the use of thickened fluids

Frequently Asked Questions

No. Special caution is needed, especially for premature and young infants. Xanthan gum-based thickeners like SimplyThick are contraindicated in infants under 12 months due to the risk of necrotizing enterocolitis (NEC).

Thickeners can cause dehydration indirectly. Many patients consume less liquid due to poor taste, undesirable texture, or early satiety, which reduces their overall fluid intake and can lead to dehydration over time.

Yes, thickeners can significantly delay the dissolution and absorption of medications. It is critical to inform your doctor and pharmacist about thickened liquid use so they can advise on proper administration and timing.

Even with thickeners, patients remain at risk for aspiration. Thicker liquids can increase pharyngeal residue, and if aspiration still occurs, it may be silent or lead to complications. Thickeners do not eliminate the risk entirely.

Starch-based thickeners are broken down by salivary amylase, an enzyme present in saliva. This enzymatic action can cause the liquid to thin while it's in the mouth, potentially increasing aspiration risk.

Common side effects include constipation, bloating, gassiness, changes in bowel habits, and a feeling of early fullness. These can negatively impact nutrition and quality of life.

You should reconsider thickener use if you observe signs like reduced fluid intake, weight loss, increased thirst, or frequent chest infections. Any change in swallowing function warrants a reassessment by a healthcare professional.