The short answer is that it's best to refresh the userform rather than try to reload it.
I guess you've got form initialisation code in the load or initialise event of your form. This code fills your text boxes and combo boxes.
I suggest you seperate out this code into a Private Function or Sub still within the same form which does this initialisation. You call this sub on the form load or initialise event, and you call it again on the click event of your command button. (This code should also clear the contents of combos before filling them so you don't fill it twice.)
Are you just trying to clear the textboxes, optionbuttons, and checkboxes? like a reset?
if so this will do it for you
Private Sub Reset_Click()
Dim ctl As Control
For Each ctl In Userform_name_here.Controls
If TypeName(ctl) = "TextBox" Then ctl.Text = Empty
If TypeName(ctl) = "ComboBox" Then ctl.Text = Empty
If TypeName(ctl) = "OptionButton" Then ctl.Value = False