Bioenhancers are specialized substances that, on their own, do not possess medicinal properties but when combined with an active drug, enhance the pharmacological effects of that drug. Each year, numerous drug molecules are introduced into the market, but many of them face challenges such as poor solubility, stability, bioavailability, and adverse side effects. Among these issues, low bioavailability is a significant problem that can be addressed. Several factors contribute to low bioavailability, including low lipophilicity, zwitterionic nature at physiological pH, and poor water solubility. Herbal bioenhancers have demonstrated the ability to improve the bioavailability and efficacy of various drug classes, including antibiotics, antituberculosis drugs, antivirals, antifungals, and anticancer medications, at lower doses. They have also been effective in enhancing the oral absorption of nutraceuticals such as vitamins, minerals, amino acids, and certain organic compounds. Examples of compounds used as bioenhancers include curcumin, piperine, quercetin, cow urine, cinnamon bark, black cumin seeds, and capsicum fruits. It is noteworthy that nearly all spices exhibit bioenhancing activity. Currently, herbal bioenhancers represent a novel approach in modern medicine due to their advantages such as improved bioavailability, safety, absence of side effects, reduced drug toxicity, shortened treatment duration, and lowered treatment costs. This review explores various herbal bioenhancers and their mechanisms of action in detail.