First we need to know the reason why the child has no friends, is why conflict situations, and maybe guys just do not take your teenager and recorded it in the rogue. Unobtrusive, openly talk to your child, having ascertained the cause, act on the situation. Help to develop in the right direction. Determine what qualities are missing in your teenager, confidence, independence and so on. Help your child work on strengthening the necessary qualities.
Help your child closer to the interests of the company, which wants to be a teenager. If the guys doing photography, music, sports, other Hobbies, enroll your child for the appropriate class. Don't let the young person tends to look as friends and it will have to do an intricate hair style and buy new jeans.
If a teenager, because of his impulsiveness, had a fight with a friend and decided to end the relationship, stop it. Ask them to tell you the cause of the conflict, analyze the situation together, maybe the conflict is not so serious to alienate friends. Teach your child to appreciate people, to forgive, to give second chance.
If the teenager is too shy, it would be hard to get along with people, then you need to work on his confidence. Help your child look more attractive, a new hairstyle, stylish clothes, a teenager should look neat and tidy and like himself. Send it to fitness, in a sort of hall, self-confidence will add a nice trim figure. Also help special training, or courses that develop communication skills and struggle with shyness.
All people are very different and aim to please everyone, to be interesting for everyone is impossible. Encourage your teenager to be yourself and love yourself for what it is. People don't like hypocrisy and pretense. When the child will perceive himself, he will attract friends who have similar interests with him.
To establish the child's ability to communicate, parents every day to give it time to talk about everything. Ask questions, encourage your child to talk more, teach him to hold a conversation, find a new topic of conversation.