Oral medications are the most common due to convenience, patient preference, cost, and easy manufacturing. Oral medications take up 60% of the market for commercial drugs. Furthermore, 84% of top-selling brand drugs are oral. With a market valued at just over $35 billion with 10% annual growth, Oral medications have an exorbitant market share. Though oral drug delivery is convenient, it still has challenges, such as poor solubility, due to which only a minimal amount of the drug reaches the bloodstream. These poorly soluble drugs also have difficulty in dissolving and permeating in the gastrointestinal tract. In addition, these drugs can be destroyed by the acidic environment present in the stomach and intestines, hence resulting in fewer active drugs being left in circulation. In recent years, advances stemming from the field of nanotechnology and nanomedicine have contributed to the development and assimilation of nanocarrier systems for the oral delivery of drugs. Nanomedicine is particulate matter developed at a nanoscale (1 to 1000 nm). Some of these nanometer-sized particles have a propensity to act as carriers in different modes of pharmaceutical delivery systems. After injection by the intravenous route, these nanoparticles have the ability to remain in circulation for long periods of time with a slight reduction of the renal clearance compartment because of their small physical size and high drug loading and encapsulation efficiency. They allow for sustained or controlled release of drugs, which increases bioavailability and lowers the number of doses. This technique can also solve the problem of drug resistance because it enables cells to internalize more of the drug. In addition, nanoparticles can be designed to contain targeting ligands, which increases the delivery of drugs to desired sites and reduces the amount of drugs delivered to normal tissues. Various polymers, spanning natural, synthetic, and semisynthetic categories, are used to create nanoparticles for drug delivery. Among these, chitosan and its derivatives stand out, particularly for oral administration. The most important derivative of chitin is its chitosan, the latter appearing when the acetate group is removed from chitin. The distinct character of chitosan, in particular its cationic charge owing to amino groups, helps drugs to easily cross the barrier and shows great adhesion to mucosal tissues. Presently, it is also the most common mucoadhesive polymer used for oral delivery of proteins and peptides. Moreover, chitosan possesses other attractive characteristics, including being biodegradable, biocompatible, and low in toxicity, which makes it ideal for use in pharmaceuticals. Chitosan is a polysaccharide consisting of N-acetyl-d-glucosamine and d-glucosamine linked by 1-4-β-glycosidic bonds and is produced through the deacetylation of chitin in an alkaline medium. Chitosan nanoparticles (CSNPs) are the most advantageous in cases of ocular as well as oral drug delivery systems. Chitosan can be obtained from the fungal cell wall and prawn and crab shells. In particular, transformed chitin consists of chitosan obtained as a result of the deacetylation of purified chitin. The degree of deacetylation can be adjusted using variables such as concentration, chitin to alkali ratios, temperature, the chitin source, and reaction extent etc. to control the final product properties, such as molecular weight and a desired pKa (6 -7.5). CSNPs have proven to successfully solve challenges in the current insulin delivery method, which is infamous for frequent injections and reduced patient compliance. Preparation methods like coacervation and spray drying are used to create these CSNP carriers, which have shown promise in preclinical studies as oral insulin carriers despite the need for further improvements. Modifying chitosan through techniques like thiolation and grafting can enhance its solubility, permeability, and insulin protection in the gastrointestinal tract. Various chitosan carriers such as nanoparticles, microparticles, and beads have shown potential in improving insulin absorption in the colon. This review aims to examine the synthesis methods, key properties, and bioavailability-enhancing mechanisms of chitosan nanoparticles, with a particular focus on their mucoadhesive capabilities and protective roles in the gastrointestinal tract and how they are currently advancing in the healthcare and nanotechnology market.