Alchemy and astrology are forever tied together as one and the same...
Being aware of your own astral birth chart, the current lunar, star and planetary phases, and how it effects and interacts with your substances, and your own birth chart, is critical to traditional alchemy.
In fact, some of the founding fathers of alchemy said treating a patient who was sick was not about which herb + medicine to use... It was about the metaphysical properties of each herb in relation to the currently placement of stars + planets and how that relates to the patient being treated.
Using the patients individual astrological birth chart, and the current astrological conditions, only then can a proper herb be selected for their treatment.
Using the same herb for all people for all conditions was absurd to them, as these interplays of cosmic forces at different times activated the medicine within each herb individually.
Check out some of the classic works of Paracelsus... a founding father of Alchemcy, esteemed physician, astrologer, and esoteric occult researcher.
-Eternally Romping the Astral Savannahlands-