 Allergy Therapeutics AT has developed formulations over the years to increase both the safety and efficacy of such treatment. In particular, the allergen extract has been chemically modified with glutaraldehyde and formulated with L-tyrosine to act as a depot adjuvant and provide a slow release of the allergens or modified allergens. This increases the safety profile and enhances the efficacy-associated immunological changes. Efficacy could be further improved by adding the immunological adjuvant monophosphoryl lipid A MPL. 