MySQL - How to search for exact word match using LIKE?

I'm using this query to select data:

mysql_query("SELECT * FROM products WHERE product_name LIKE '%".$search."%'");

The only problem is, that it sometimes selects more, than I would like.

For example, I would like to select product "BLA", but my query select product "BLABLA" as well. To be clear, if i wanted to select "Product 1", I don't want the query to select "Product 11".

Does anybody know how to manage that?

Thanks.