No...I am not going to discuss the remedies for Moon out here or any medicines associated thereof. I just wanted to tell that Moon is one planet which gives natural inclination towards chemistry and chemicals. And chemicals (natural and man-made) are used for making medicines. Someone who has a good Moon, preferably in first house or 10th house will give the native a propensity towards medicines/chemicals. A person with good moon will always be good in Chemistry and Biology (specially Botany). If Jupiter is involved the medicines will mostly be natural and the native will be involved in chemistry of natural substances. For example a doctor of Ayurvedic medicines will have a good Moon, Jupiter and may be Sun too. If Saturn get involved with Moon or aspects it, the native will have inclination towards Homeopathy, Allopathy etc. That's why in a doctor's chart, these 3 planets must form a combination. Mercurians (people with Virgo and Gemini ascendant) have a strong inclination towards profession of doctors. Now, if Mars also comes along to play some role, the doctor will become a good Surgeon too.
On the whole for becoming a doctor, you need to have a good Moon, Saturn, Jupiter (ensuring higher education) and Mercury (Mercury will also help in cracking the competition).