Medicines in Ayurveda are mostly derived from herbs (all parts of herbs) and other plants.  Some metal and mineral powders are also added to these or used separately in some preparations.

Kashayams are prepared from fresh herbs (whenever possible) by boiling them in large quantities of water till the essence is drawn into water, i.e., when the volume of water is reduced to one-fourth or less of the original volume by boiling over a low flame for a long time.  It is stored in airtight glass bottles and cannot be kept long.

Asavas/Arishtas are prepared by natural fermentation of herbal preparations and can be stored for a long time.  Fresh herbs or water soaked dry drugs are used for asavas and decoctions of several herbs are used for arishtas.  These also should be kept in airtight glass containers.

Medicated oils (Thailams) are medicated oils mostly used for external application, though a few can be consumed as part of medication either alone or in combination with kashayams.  These contain the extracts of fat-soluble herbs, animal and mineral products, prepared in sesame oil, coconut oil, castor oil or neem oil. There are stimulating Thailams and soothing counter-irritants.  They can be kept for 2 years if kept away from direct sunlight.

Lehyams and Rasayanams are preparations with the look and consistency of jam or very thick paste. They are extracts of a single or several herbs or medicinal plants, or a combination of such medicinal ingredients with animal and/or mineral products/by-products, which are thickened into a paste form. They may be called electuaries and can be stored in wide-mouthed bottles or jars.

Ghritam is ayurvedic ghee. It is actually clarified butter derived from milk. Various herbal extracts are added to the clarified butter to make ghritams used as remedies for several diseases in Ayurveda and Siddha.

Chooranams  are herbs made into powdered form. In the dry powder form the medicine can be kept for long periods without any loss of properties.  Kwatha Chooranams are also chooranam (powdered herbs) that has to be taken in the form of decoction and not straight in the powder form.  Chendurams (Bhasmam) is powdered metals and/or minerals obtained through calcinations and/or sublimations mixed with water, honey, etc. All the powdered medicines are now available in the form of tablets also.