The 5mg amount shown here describes this PEPTAS listing, not a protocol or recommended quantity for an experiment
Gregg EW, Jakicic JM, Blackburn G, Bloomquist P, Bray GA, Clark JM, Coday M, Curtis JM, Egan C, Evans M, Foreyt J, Foster G, Hazuda HP, Hill JO, Horton ES, Hubbard VS, Jeffery RW, Johnson KC, Kitabchi AE, Knowler WC, Kriska A, Lang W, Lewis CE, Montez MG, Nathan DM, Neiberg RH, Patricio J, Peters A, Pi-Sunyer X, Pownall H, Redmon B, Regensteiner J, Rejeski J, Ribisl PM, Safford M, Stewart K, Trence D, Wadden TA, Wing RR, Yanovski SZ
A small sample makes both the positives and the negatives statistically less stable
However, you may need to drink more or less water depending on your level of activity, the local climate, and your medical conditions
Per-milligram pricing is typically 10-20% higher for smaller vials