[9] In contrast to larger photosensitizer molecules, it is predicted by computer simulations to be able to penetrate tumor cell membranes.

[6] Studies since 2006 have shown that the intraoperative use of this guiding method may reduce the tumour residual volume and prolong progression-free survival in people with malignant gliomas.

When administered to patients, 5-ALA is metabolized to protoporphyrin IX (PpIX) preferentially in cancer cells, leading to their fluorescence under specific light wavelengths.

[17] This fluorescence aids surgeons in real-time identification and precise removal of cancerous tissue, reducing the likelihood of leaving residual tumor cells behind.

[12] In non-photosynthetic eukaryotes such as animals, fungi, and protozoa, as well as the class Alphaproteobacteria of bacteria, it is produced by the enzyme ALA synthase, from glycine and succinyl-CoA.

[27] Cancer cells lack or have reduced ferrochelatase activity and this results in accumulation of Protoporphyrin IX, a fluorescent substance that can easily be visualized.

[28] Biliverdin and Bilirubin are potent anti oxidants and regulate important biological processes like inflammation, apoptosis, cell proliferation, fibrosis and angiogenesis.

[4] Plants that are fed by external 5-ALA accumulate toxic amounts of chlorophyll precursor, protochlorophyllide, indicating that the synthesis of this intermediate is not suppressed anywhere downwards in the chain of reaction.