Final answer:
The extraction method used for medicinal compounds is likely extraction, but fractional crystallization, as described, is a purification technique based on solubility differences.
Step-by-step explanation:
The extraction method typically used to obtain medicinal compounds such as the active ingredients in Cold Sore Relief (CSR) is likely to be extraction. However, the process you've described, fractional crystallization, is used for purifying compounds. It involves dissolving a compound in a solvent at a high temperature where it is more soluble and then lowering the temperature so it crystallizes, separating from impurities that remain dissolved. This method relies on the different solubilities of compounds at various temperatures and is not directly an extraction method but a purification technique.