Definitely the solvent content. To suspend 200mg of cyp, suppliers usualy use ~5%ba. To add another 200mg of enant., they probably add additional BA to prevent it from crashing.
That and highly concentrated shots just hurt more, causing more inflammation due to lack of the buffer (i.e., oil).
Get used to it... At 400mg/ml its going to continue. You can always tell who uses the T400 by how they hang an asscheek off of one side of the bench.
should i cut it with grapeseed oil?