You think we are tough with our 21-23g pins? Well, it is certainly more than a flu shot, but it is not the worst you can experiance. I do not know what they use for spinals and all that, but I did go to an American Red Cross Blood drive this summer. They stuck me in that vein in the middle of your arm that they always love to take blood from. It was a huge needle. Ever since I have been juicing and get blood drawn or get a shot I ask them what gauge they are using. They probably just think I am a herion user or something, but at any rate ... THE RED CROSS USES 16 GAUGE PINS TO EXTRACT BLOOD!! Hurts like hell, but I suppose it moves the blood fast.