Possible causes of metallic taste
1. Viral infections (including COVID-19)
COVID-19
COVID-19 can affect taste and smell because the virus can impact:
- taste receptors
- smell pathways (which strongly influence taste)
- nasal and sinus lining
People may notice:
- metallic taste
- reduced taste or smell
- distorted taste (food tastes “off”)
This can also happen with other viral infections, not just COVID.
2. Dental or oral health issues (very common)
- Gum disease
- Tooth infections
- Poor oral hygiene
- Tongue coating or bacteria buildup
- Recent dental procedures
These are among the most frequent causes of metallic taste.
3. Medications and supplements
Many medicines can change taste, including:
- antibiotics
- antihistamines
- blood pressure medications
- antidepressants
- iron or zinc supplements
4. Sinus or respiratory problems
Sinusitis
Sinus infections or congestion can:
- affect smell
- distort taste perception
- cause post-nasal drip (bitter/metallic taste)
5. Nutritional deficiencies
Low levels of certain nutrients can affect taste:
Iron deficiency anemia
Also:
- zinc deficiency (very linked to taste changes)
- vitamin B12 deficiency
6. Acid reflux or stomach issues
Gastroesophageal reflux disease
Symptoms may include:
- sour or metallic taste
- burning in chest or throat
- worse after eating or lying down
When it may need medical attention
You should consider evaluation if:
- taste change lasts more than 1–2 weeks
- it happens along with loss of smell
- you have persistent fatigue or weakness
- there is unexplained weight loss
- oral pain, swelling, or infection signs are present
When it is usually harmless
It is often temporary if:
- it started during a cold or viral illness
- it is linked to a new medication
- it improves within a few days
- oral hygiene is poor but improves with cleaning
Conclusion
A metallic taste in the mouth can sometimes be related to COVID-19 or other viral infections, but more commonly it is caused by dental issues, medications, sinus problems, acid reflux, or nutritional deficiencies, and it usually improves once the underlying cause is treated or resolved.