Charak Samhita
रसायनानां विधिवच्चोपयोगः शस्यते। शस्यते देहवृत्तिश्च भेषजैः पूर्वमुद्धृतैः ॥१४॥
For them, the proper use of rasayana chikitsa (rejuvenation treatment) is recommended and maintenance of the body by means of medicinal herbs collected before the onset of epidemics is recommended.
english translation
rasAyanAnAM vidhivaccopayogaH zasyate। zasyate dehavRttizca bheSajaiH pUrvamuddhRtaiH ॥14॥
hk transliteration by Sanscript