The question of which is better depends partly on what result you are actually trying to achieve
Multiple cellular processes are considered to contribute to this functional decline and these are collectively referred to as the hallmarks of aging and these include processes like genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, disabled macroautophagy, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis 1
Nasal sprays may deliver GSH across mucosal membranes, offering another route for rapid uptake
Sragovich S, Merenlender-Wagner A, Gozes I