What causes a soapy taste in the mouth?
People describe a soapy taste as being:
- slightly metallic
Eating soap is a surefire way to get this unpleasant sensation, but it is not the only reason for a soapy taste in the mouth.
On its own, a soapy taste in the mouth does not reveal much about a person's overall health.
It is important to look at a variety of factors, such as what a person recently ate, any medications they take, and their health history, to disagnose the cause of the soapy taste.
Seven potential causes
Here, we describe some common reasons why a person might have a soapy taste in their mouth:
1. Contaminated food or drink
A person may have a soapy taste in the mouth if they eat from dishes that they have not rinsed thoroughly.
The taste of soap is so strong that even a trace of it can change the taste of food and water.
A soapy taste in the mouth may happen if a person:
- eats off dishes they have failed to rinse properly
- washes vegetables or fruit in water that has soap in it
- uses washed drinking straws that still have soap residue inside
- prepares food when they have soap left on their hands
The taste of soap in a person's mouth usually goes away over a short time in these instances.
Some medications leave a taste in the mouth. This flavor can resemble soap or can interact with food or water to create a soapy or metallic taste. If the soapy taste occurs with a new medication, the drug is probably the culprit.
This symptom is harmless but can be annoying. It typically lasts as long as a person takes the drug.
3. Stroke or brain injury
Every taste and flavor requires the taste buds to send signals to the brain. If the brain cannot correctly process or understand these signals, it can change the way food tastes.
Some people experience changes in the way food tastes during or after a stroke or other brain injury. Others are not able to detect flavors at all. A soapy or metallic taste after a stroke may be temporary or long-term.
If a person experiences changes in their sense of taste, they should consult a doctor who can diagnose the cause. Occupational, speech, or swallowing therapy may be helpful.
Anxiety affects the brain and body in a variety of ways. People experiencing anxiety about their food, the way it tastes, or the potential for contamination may find their perceptions of specific tastes change.
People who taste soap on their food and who become anxious about its potential health effects may create a self-fulfilling prophecy. In other words, by anticipating more soapy tastes, the brain may perceive a soapy flavor even in the absence of one.
5. Genetic responses to coriander and some other foods
A variant in the gene OR6A2 can make some foods, especially cilantro or coriander, taste unpleasant and sometimes like soap. The variant is relatively rare.
The gene does not mean a person has an underlying health problem. Instead, it only causes certain foods to taste bad.
6. Oral health issues
Oral health issues can cause a soapy taste in the mouth.
Problems with gum and tooth health can cause a soapy or metallic taste in the mouth. If a person does not maintain good oral hygiene, old food may be left behind in the teeth and gums, changing the way food tastes.
Gum disease can cause a soapy taste in the mouth. Some people also notice a strong metallic taste. Various mouth and tooth infections also cause unusual tastes in the mouth.
If a soapy taste occurs with jaw or tooth pain, swollen or red gums, or bad breath, people should consult a dentist.
A number of poisons can change the way food tastes or cause a soapy or metallic taste in the mouth. An example of this is arsenic, which may affect the way food tastes.
Poisoning is more likely in children and babies and people who have:
- eaten food that may be contaminated
- consumed contaminated water
- been exposed to polluted air
- been exposed to potentially contaminated enclosed spaces
A soapy taste may be the first symptom of poisoning, but most people quickly experience other symptoms, such as:
- changes in consciousness
Treatment and home remedies
A soapy taste alone does not necessarily require treatment.
If a person has no reason to believe they are facing a medical emergency, such as possible poisoning, they can usually wait to see if the symptoms disappear.
Some strategies that may help include:
- drinking water from a reliable source, such as bottled or filtered water
- eating bland food to help get rid of the taste of other foods
- brushing and flossing the teeth to remove plaque or decaying food
- meditating and deep breathing to help relieve anxiety
When to see a doctor
A person should consult a doctor if the soapy taste gets more intense.
A soapy taste in the mouth is not typically a serious condition. However, people should see a doctor within 1 to 2 days if:
- the taste does not go away on its own
- the taste gets more intense
- the taste occurs with stomach problems, such as vomiting
People should go to the emergency room if:
- a soapy taste in the mouth happens after a head injury
- there are signs of a stroke, such as changes in thinking or a droopy face
- there are other symptoms, such as a loss of consciousness
- a child complains of a soapy taste in the mouth
- they have eaten large quantities of soap
- they were exposed to potentially toxic substances, contaminated food, or dirty water
The taste buds do not always accurately reflect the taste of food. A soapy taste in the mouth is unpleasant but does not often mean that something serious is wrong.
If someone is in doubt about the reason for the soapy taste, or it does not go away quickly, they should consult a doctor.