Described herein are improvements relating to IGF-1 analysis, adjustment and disease management of non-neurological and/or neurological conditions. More specifically, methods relating to the clinical application of cyclic glycine-proline (cGP) biomarker for prediction of risk and recovery of non- neurological and/or neurological conditions with IGF-1 dysfunction and the use of a cGP containing organic or plant based material such as concentrated extract of blackcurrant anthocyanins (BCA) for the treatment of same. The methods more accurately measure IGF-1 function in vivo indirectly using cGP and cGP/IGF-1 ratio along with a means to adjust cGP and cGP/IGF-1 ratio (and hence active IGF-1 concentration), and specific treatment methods for individuals with a lower or reduction of cGP level relative to a standard set of baseline data.