High5 isogel xtreme 60ml x 25isogel xtreme is the latest high caffeine gel in high5s award winning sports nutrition range you can use isogel xtreme gels to pre load with caffeine before an event or take it for that extra edge towards the end of a race to increase alertness concentration and improve performance easy to open and swallow each sachet contains 23g of carbohydrate energy and a high dose of caffeine 100mg high5 isogel is a fresh tasting gel that is not thick or overly sweet u