Placebo: 2% (w/v) L-tyrosine and 0.5% (w/v) phenol for subcutaneous use clinical trials

A randomised, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of PQ Birch in subjects with seasonal allergic rhinitis and/or rhinoconjunctivitis induced by birch pollen exposure

This study is testing a new treatment for hay fever caused by birch pollen. It compares the new treatment with a dummy treatment (placebo) to see if it helps reduce hay fever symptoms like sneezing and itchy eyes, and if it's safe to use.