The present invention discloses cosmetic or topical pharmaceutical compositions for body slimming, firming, cellulite reduction, fat-reduction, and obesity control benefits that can be selective and specific for external body parts and organs such as face, chin, cheeks, arms, "love handles" in abdomen area, eye lids and eye zone, neck, breasts, thighs, and hips. These compositions include a synergistic, bioavailability-enhanced ion-pair combination of Hydroxycitric acid or Hydroxycitric acid derivatives with certain organic bases such as Niacinamide, Niacin, Pyridoxine, Aminophylline, Caffeine, Carnitine, Creatine, Chitosan, Allantoin, Glucosamine, Phaseolamine, Chromium Picolinate, Theobromine, Theophylline, and such.