Concept:
• A general rule in Ayurvedic pharmacy (Bhaishajya Kalpana) states that when a drug is used in its fresh/wet (Ardra) state, its quantity should be doubled compared to its dry state to account for moisture content.
• However, there are specific exceptions to this rule for drugs that are highly potent or have specific properties in their fresh form.
Step 1: The "Double Quantity" Rule
The standard Paribhasha (definition) states: "Ardra dravyam tu dvigunam".
If a formula calls for 10g of a dry herb, and you only have fresh herb, you should use 20g.
Step 2: Identifying the exceptions
Certain drugs are so naturally potent or have such high therapeutic efficacy in their green/fresh state that doubling them would lead to an overdose or excessive bitterness/potency.
According to classical texts (Sharngadhara Samhita), the primary exceptions are:
Guduchi (Tinospora), Kutaja (Holarrhena), Vasa (Adhatoda), Kushmanda, Shatavari, and Sahachara.
Step 3: Clinical Logic
For Guduchi, Kutaja, and Vasa, the fresh juice or the fresh plant material is considered superior.
Therefore, they are used in the same quantity as prescribed in the formula, without doubling (Sama-bhaga).