5-Aminolevulinic acid hydrochloride is a specialty chemical used primarily in medical and dermatological fields as a precursor in the biosynthesis of heme. In photodynamic therapy (PDT), it is applied to treat skin cancers such as basal cell carcinoma and squamous cell carcinoma, as well as actinic keratosis, by converting into protoporphyrin IX (PpIX), a photosensitizer that, when exposed to specific light or laser, destroys abnormal cells. It also aids in the diagnosis of bladder cancer through intravesical administration followed by fluorescence imaging to detect malignant tissues, enhancing diagnostic accuracy.

Additionally, it supports visualization of cancerous tissues during fluorescence-guided surgeries, improving tumor removal precision. In aesthetic applications, it is used in PDT to treat acne and improve skin conditions by reducing inflammation and eliminating bacteria upon light activation.

In agriculture, it serves as a plant growth regulator, promoting healthier and more robust plant development. Its use requires supervision by medical professionals or experts to ensure safety and efficacy.