In addition to your local pharmacy, drug store or supermarket, you can purchase Just For Men online at these sites

Just for Men can be found at the following online retailers:
Allcures.com
Boots/Wellbeing.com
Chemist Direct
Pharmacy2U.co.uk
Mgender.com
Mankind
Poshgeezer
Blushing Buyer Chemist-4-u.com

And at retail stores such as these:
Boots, Superdrug, Tesco, Sainsbury, Asda, Morrisons, Waitrose, Wilkinsons, Savers, Bodycare, Semi chem, Lloyds Pharmacy, Moss Pharmacy and Independent Pharmacies