Small molecules are low molecular weight organic compounds that can easily enter cells and affect biological processes. They are typically administered orally and can target intracellular pathways. Examples include antibiotics, analgesics, and synthetic hormones. Due to their small size, they can often cross cell membranes and reach intracellular targets, making them highly effective in modulating various biological functions. Additionally, small molecules can be designed to have high specificity and potency, which is crucial for minimizing off-target effects and enhancing therapeutic efficacy.