3 doctors weighed in:

Why is it that allergy pills don't work every time I take one?

3 doctors weighed in
Dr. Stephen Kimura
Internal Medicine - Allergy & Immunology
1 doctor agrees

In brief: Timing

Antihistamines work by blocking histamine receptors in your body.
If the receptors are all full of histamine already (reaction has occurred), then there is nowhere for them to go and it will not make a difference in allergy symptoms. If you take them before exposure to allergens they can block the receptors and you will have less symptoms.

In brief: Timing

Antihistamines work by blocking histamine receptors in your body.
If the receptors are all full of histamine already (reaction has occurred), then there is nowhere for them to go and it will not make a difference in allergy symptoms. If you take them before exposure to allergens they can block the receptors and you will have less symptoms.
Dr. Stephen Kimura
Dr. Stephen Kimura
Thank
Dr. Lee Perry
Internal Medicine - Allergy & Immunology

In brief: Many possibilities

Allergy medications are not 100% effective in treating allergic diseases (like hayfever).
These medicines are marginally effective in some patients, who often require allergy shots to truly get relief. Another possibility is that you may be treating a non-allergic condition.

In brief: Many possibilities

Allergy medications are not 100% effective in treating allergic diseases (like hayfever).
These medicines are marginally effective in some patients, who often require allergy shots to truly get relief. Another possibility is that you may be treating a non-allergic condition.
Dr. Lee Perry
Dr. Lee Perry
Thank
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