Something's Rotten in Faerun
Potion of Growth
Growth: This potion causes the height and weight of the person consuming it to increase. Garments and other worn and carried gear also grow in size. Each fourth of the liquid consumed causes 6 feet of height growth—in other words, a full potion increases height by 24 feet. Weight increases should be proportional to the change in height. Strength is increased sufficiently to allow bearing armor and weapons commensurate with the increased size, but does not provide combat bonuses. Movement increases to that of a giant of approximately equal size.