Grastek (Timothy Grass Pollen Allergen Extract)

What is Grastek (Timothy Grass Pollen Allergen Extract)

Grastek is a prescription medicine used for sublingual (under the tongue) immunotherapy to treat Timothy and related grass pollen allergies that can cause sneezing, runny or itchy nose, stuffy or congested nose, or itchy and watery eyes.

This medicine may be prescribed for persons 5 through 65 years of age who are allergic to grass pollen.

Brand Name



  1. Immunotherapy for the treatment of grass pollen-induced allergic rhinitis with or without conjunctivitis confirmed by positive skin test or in vitro testing for pollen-specific IgE antibodies for Timothy grass or cross-reactive grass pollens. 

Side Effects

  1. ear pruritus
  2. oral pruritus
  3. tongue pruritus
  4. mouth edema
  5. throat irritation