Shahid Kapoor lost 14 kg of weight to do Kabir Singh.
Film's director Sandeep Reddy Vanga thought of giving the lead role to Shahid Kapoor after watching trailer of 'Udta Punjab' , when his film Arjun Reddy was in pre-production.
Ashwin Varde who acquired the rights wanted Arjun Kapoor for lead.But Sandeep Vanga had already signed Shahid Kapoor.
Director Sandeep Vanga Reddy was shooting for his film Arjun Reddy when his son was born. So, while in the midst of the shooting, he decided to name his son after the character of the movie. So, apparently the name of his son is Arjun Reddy. The director has officially revealed this in some of his interviews.
Sandeep Reddy Vanga shot the portion in which Shahid Kapoor have a look with long hair and beard, then shot the part when there are long hair and no beard and then shot the part in which he has a normal look,
If they shot in a sequence, they have to wait for four months to get a new look.