Thanks for the advice. I think for me it's the combination of Methylchloroisothiazolinone and Methylisothiazolinone as preservatives - I've heard that people can have a sensitivity to these two in leave-in products, and I've used other products with Propylene Glycol without a problem.

I've seen a lot of great recommendations on this board - I guess I was looking for someone who had tried a product very similar to Biotera so I could make use of people's experience - I want Biotera without these preservatives!