Backup? Pros: cheaper than 100% Pure. Cons: No hyaluronic acid like 100% Pure.

Primary niacinamide

Primary, but out of stock. Pros: 3 types of Vitamin C, in powder form, and contains hyaluronic acid, too. Cons: more expensive and currently out of stock

Backup vitamin C? Pros: cheaper than 100% pure, in stock Cons: no hyaluronic acid, only one type of Vitamin C.

Backup vitamin C? Pros: much cheaper than 100% Pure Vitamin C Boost, in stock Cons: 100% Pure has 3 types of Vitamin C and hyaluronic acid

Sugarcane squalane type is best

From sugarcane

Occlusive. Used to lock in moisture and products at night and prevent wrinkles for years. But, not a good idea if you're prone to milia bumps.

Olive based

From olive

Squalane works well for retinol. Seen here but also in another review for another squalane https://amarabeauty.com/products/squalane-oil

From olives

Sugarcane

Acne prone good https://www.skinstore.com/clarityrx-nourish-your-skin-100-percent-squalane-additive-oil-1-fl.-oz./12901338.html?switchcurrency=USD&shippingcountry=US&nrtv_cid=ed125c3c1b2a8e2e213ed60433ea57b1531277807db83c52eec1a5a782e6cd51

Only 4 ingredients. https://www.revoxb77.com/products/retinol-in-squalane