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Basics5 min read2025-02-10

When to Start Taking Hay Fever Medication

Timing matters when it comes to hay fever treatment. Learn when to start your medication for the best symptom control during UK pollen season.

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This article is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a GP or qualified healthcare professional before starting, stopping, or changing any medication.

One of the most common mistakes hay fever sufferers make is waiting until symptoms are severe before reaching for medication. By that point, your body's allergic response is already in full swing, and it takes longer for treatments to bring it under control. Starting early can make a significant difference to how well you manage the pollen season.

The Two-Week Rule for Steroid Nasal Sprays

Corticosteroid nasal sprays — such as Beconase, Pirinase, and prescription sprays like Nasonex — need regular daily use for up to two weeks before they reach their full anti-inflammatory effect. The NHS and allergy specialists recommend starting your steroid nasal spray at least two weeks before your trigger pollen season begins.

For most people in the UK allergic to grass pollen (the most common trigger), this means starting your nasal spray in late April or early May. If tree pollen is your trigger, you may need to start as early as late February or March.

Antihistamine Tablets

Oral antihistamines like fexofenadine, cetirizine, and loratadine work more quickly — usually within one to three hours. However, taking them before symptoms start is still more effective than waiting. Many allergy specialists recommend beginning daily antihistamines one to two weeks before the season, especially if you know your triggers well.

Know Your Pollen Triggers

The UK pollen season is broadly divided into three phases:

  • Tree pollen: late February to mid-May (birch, oak, ash)
  • Grass pollen: mid-May to July (the peak hay fever period)
  • Weed pollen: late June to September (mugwort, nettle)

If you are unsure which pollen affects you, keeping a symptom diary or asking your GP about allergy testing can help you pinpoint your triggers and plan medication timing accordingly.

Practical Tips for Getting Ahead

  • Check the Met Office pollen forecast from March onwards
  • Stock up on medication before the season — pharmacies can run low during peak demand
  • Set a daily reminder so you do not miss doses of your nasal spray or antihistamine
  • If your symptoms were poorly controlled last year, speak to your pharmacist or GP before the season starts to discuss stepping up your treatment plan

Starting early is the single most impactful step you can take for better hay fever control.