A 10 month old baby , a FTND with BW 3.0 kg, exclusively breast fed for 6 month then weaning started, no other complains other than not growing well as still his wt is 3.0 kg came to me for further management . I investigated first routines like CBC mp CRP Vit d level, s alkaline po4 thyroid profile,IGF1, all reports are wnl except IGF 1 which came half than normal so it's an GH deficiency so how can I start Gh treatment?

Please suggest.