Introduction: Despite effective treatments, asthma outcomes remain suboptimal. Interest exists in herbal remedies. Aims: To evaluate AKL 1, an herbal mixture, in a randomised double blinded placebo controlled cross-over trial. Methods: 32 asthmatics (8 male, median (range) age 40.5 (22-73) yrs., median (range) FEV1% predicted 87.5 (33-126)%, median (range) daily ICS dose 800 (0-4000) mcg beclomethasone) completed a 36 week trial consisting of; four week baseline, twelve-week treatment with AKL or identical placebo, eight week washout and further twelve-week crossover treatment period. The change occurring over treatment periods was observed for lung function, Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ), Leicester Cough Questionnaire (LCQ) scores. The mean (95% Confidence Interval) individual patient changes between active minus placebo periods was calculated. Results: No significant differences in lung function (active-placebo) were found (FEV1: mean (95% CI) difference = 0.01 (−0.12 to 0.14)L, p = 0.9. PEF: −4.08 (−35.03 to 26.89) L/min, p = 0.8). Trends to clinical improvements favouring active treatment were however consistently seen in the patient-centred outcomes: ACQ mean difference (active − placebo) = −0.35 (−0.78 to 0.07, p = 0.10, AQLQ difference 0.42 (−0.08 to 0.93, p = 0.09), LCQ difference 0.49, (−0.18 to 1.16, p = 0.15). With a change in ACQ and AQLQ score of 0.5 signifying a clinically relevant changes in control or health status, on the ACQ, 28% were unchanged, 22% better on placebo and 50% better on AKL, and on the AQLQ 29% had no change, 29% were better on placebo and 42% better on AKL. Nine exacerbations occurred during placebo treatment and five whilst on AKL. No significant adverse events were noted. Conclusions: AKL1 treatment was well tolerated. Consistent trends to symptom and quality of life improvements were observed, although no improvements in lung function seen. Further studies. Conflict of interest and funding None. Funding: The study was funded by Bridgehead Technologies Ltd.