These 2 PDFs offer some alternate mechanics for potions and creature sizes.
Potion sizes allows for multi-use potions, with incentives to refill, instead of replace.
Creature sizes adds 4 new creature size categories, as well as allowing for even more via a simple formula. This PDF also includes rules for climbing on massive creatures!
Shawn Pommier [Author] [https://twitter.com/EldritchDream]
Pathfinder First Edition
Pricing: This download is set to "Choose Your Price". You may purchase this for free, or you may extend your generosity to the creator for either $2.00 or $5.00. This purchase is for digital content only, and you will receive a download link for a .ZIP file containing 2 PDF files.