Phenolics are pharmaceutically important molecules. Tyrosine and tryptophan are precursors of phenolic metabolism. It was aimed to investigate the potential of exogenously introduced precursors on the phenolic contents in Trachyspermum ammi (L.) Sprague seedlings. The seeds of two local varieties (Chakwal and Desi) were grown in completely randomized design in a growth chamber at 19 ± 2°C with two amino acids (tyrosine and tryptophan) applied (priming and supplementation in rooting medium) at two treatment levels (0, and 1%). Ten days old seedlings were harvested and subjected for growth (root and shoot length, fresh weight and dry weight) and phenolic estimation was done by HPLC method. Presence of seven phenolic acids including quercitin, chromatotropic acid, gallic acid, chlorogenic acid, sinnapic acid, trans 4 hydroxy 3 methoxy cinamic acid and P-courmeric acid was confirmed in both varieties with dissimilar fraction. Poor growth was observed by "Desi" under controlled conditions that were efficiently enhanced by tyrosine and tryptophan treatments. As precursors both amino acids differed for allosteric regulation of the pathway. That varied from application to application and variety to variety too for a pattern of phenolic accumulation. In conclusion, tyrosine and tryptophan application can be useful for farmers for improved growth of T. ammi and for pharmaceutical scientists to modulate metabolites of interest.