Biopsies are vital medical technique where a small tissue sample is extracted from the body for microscopic examination. This empowers pathologists to diagnose diseases, including cancers, and scrutinize cellular structures. After tissue samples are obtained, they require fixation—a pivotal process that preserves the sample's integrity and prevents deterioration [1]. In the realm of biology and histology, preserving tissue samples is a critical step for studying and analyzing specimens. Fixatives play a pivotal role in this process, safeguarding cellular structure, preventing decomposition, and stabilizing the tissue for further examination [2]. An ideal fixative should exhibit the following desirable properties: prevention of tissue breakdown and bacterial contamination, preservation of tissue volume and structure, and avoidance of shrinkage, osmotic damage, and swelling. These characteristics are essential for achieving high-quality results in tissue preparation and analysis [3].

Formalin, an aqueous solution of formaldehyde, has endured as the preferred fixative owing to its economic feasibility, expeditious action, and adaptability across a diverse range of histological techniques. Regrettably, exposure to this compound is frequently linked to respiratory duress, mucosal irritation, and systemic toxicity [4]. The United States Environmental Protection Agency has recognized formaldehyde as a carcinogenic compound, with prolonged or high exposure posing significant health risks [5]. Consequently, the agency has set a daily exposure limit of 1 to 0.75 ppm to safeguard public health [6,7]. Moreover, the International Agency for Research on Cancer has classified formaldehyde as a Class 1 human carcinogen, which can potentially contribute to the development of various forms of cancer, including the potentially devastating nasopharyngeal carcinoma [8]. Formaldehyde exposure can cause eye, skin, and respiratory irritation; gastrointestinal corrosion; and systemic issues like metabolic acidosis, shock, renal failure, and carcinogenic effects [9]. Since traditional chemical fixatives, such as formaldehyde, often raise concerns due to their toxic nature and environmental impact, as a consequence, there has been a growing interest in exploring natural alternatives that can fulfil the same function while being more environmentally sustainable and safer for use in research and medical laboratories [10]. The alternative fixatives used in the place of formalin are honey [[11], [12], [13], [14], [15], [16], [17]], jaggery [[11], [12], [13], [14], [15],18], sugar [11,14,[18], [19], [20]] and aloe vera [19].

This comprehensive review rigorously examines and integrates the latest research on natural alternatives to the traditional chemical fixatives employed in tissue preservation. It systematically assesses the efficacy, safety, and environmental implications of plant-based and other natural fixatives, benchmarking them against conventional options such as formaldehyde and glutaraldehyde. Furthermore, the review insightfully illuminates both the advantages and obstacles of adopting natural fixatives, pinpoints critical knowledge gaps, and offers valuable recommendations to guide future investigations in this burgeoning field.