Gary Siuzdak is an American chemist best known for his work in the field of metabolomics. He is currently the Professor and Director of The Center for Metabolomics and Mass Spectrometry at Scripps Research in La Jolla, California. Siuzdak has also made contributions to virus analysis, viral structural dynamics, as well as developing mass spectrometry imaging technology using nanostructured surfaces. The Siuzdak lab is also responsible for creating the research tools XCMS and METLIN.
Siuzdak studied chemistry (B.S.) and applied mathematics (B.A.) at Rhode Island College before attending Dartmouth College where his time was split between studies and competitive powerlifting. At Dartmouth he received his Ph.D in Physical Chemistry (1990) and soon after took a position at Scripps Research. Siuzdak later authored two books: Mass Spectrometry for Biotechnology (1996) and The Expanding Role of Mass Spectrometry in Biotechnology (2003) as well as The Expanding Role of Mass Spectrometry in Biotechnology 2nd Ed. (2006). 
In 1994, while working with Richard Lerner (then president of The Scripps Research Institute), Siuzdak used liquid chromatography mass spectrometry to perform metabolomics experiments on the cerebral spinal fluid from sleep deprived animals. One molecule of particular interest, oleamide, was observed and later shown to have sleep inducing properties. This work is one of the earliest such experiments combining liquid chromatography mass spectrometry and activity metabolomics to identify active metabolites.
In 1999, Siuzdak described the use of nanostructures to enhance desorption/ionization on silicon of small molecules (DIOS). This imaging technology went on to be expanded using fluorinated gold nanoparticle substrates and was subsequently called Nanostructure Imaging Mass Spectrometry (NIMS).
- "Faculty Page, Gary Siuzdak". scripps.edu. Retrieved 22 May 2019.
- Shen, Zhouxin; Thomas, John J.; Averbuj, Claudia; Broo, Klas M.; Engelhard, Mark; Crowell, John E.; Finn, M. G.; Siuzdak, Gary (February 2001). "Porous Silicon as a Versatile Platform for Laser Desorption/Ionization Mass Spectrometry". Analytical Chemistry. 73 (3): 612–619. doi:10.1021/ac000746f.
- Scandura, Mike (30 Dec 1987). "Weightlifting the right way good for Siuzdak". The Evening Times (Pawtucket, R.I.).
- "Interview with Dr. Gary Siuzdak". MetaboNews, Issue 13 - September 2012. Retrieved 22 May 2019.
- Cravatt, BF; Prospero-Garcia, O; Siuzdak, G; Gilula, NB; Henriksen, SJ; Boger, DL; Lerner, RA (9 June 1995). "Chemical characterization of a family of brain lipids that induce sleep". Science. 268 (5216): 1506–9. PMID 7770779.
- Kurczy, ME; Northen, TR; Trauger, SA; Siuzdak, G (2015). "Nanostructure imaging mass spectrometry: the role of fluorocarbons in metabolite analysis and yoctomole level sensitivity". Methods in molecular biology (Clifton, N.J.). 1203: 141–9. doi:10.1007/978-1-4939-1357-2_14. PMC 4755109. PMID 25361674.