If you need to delete all the user creation stored procedure in SQL server database. You can use the following TSQL code snippet.

DECLARE @spName VARCHAR(128)
DECLARE @SQL VARCHAR(500)

SELECT @spName = (
	SELECT TOP 1 [name] 
	FROM sysobjects 
	WHERE [type] = 'P' 
	AND category = 0 
	ORDER BY [name]
)

WHILE @spName is not null
BEGIN
    SELECT @SQL = 'DROP PROCEDURE [dbo].[' + RTRIM(@spName) +']'
    EXEC (@SQL)
    PRINT 'Deleted Stored Procedure: ' + @spName
    SELECT @spName = ((
		SELECT TOP 1 [name] 
		FROM sysobjects 
		WHERE [type] = 'P' 
		AND category = 0 
		ORDER BY [name]
	)
END
GO

The sysobjects table contains all the non-system stored procedures created by user. We can easily identify the record by specifying the type which has a type of P that indicate it is a stored procedure type.