Sunday Riley Luna Retinol Sleeping Night Oil VS Mad Hippie Vitamin A

What's inside

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Solvent

Dimethyl Isosorbide (often shortened to DMI) is a sugar-derived solvent made from sorbitol. It's used to dissolve tricky ingredients and help them mix smoothly into a formula.

Many actives sit as gritty crystals when undissolved, so DMI swoops in to full dissolve them. This helps improve texture, stability, and how evenly an active is distributed.

It does have a penetration-enhancing reputation that is a bit more nuanced than marketing suggests; a cell study on human skin found that 10% DMI didn't significantly boost the permeation of Hydroquinone, Salicylic Acid, or Octadecenedioic Acid compared to controls (though it did improve their solubility in the formula itself).

Typical usage concentrations usually range from 1-10% depending on the formula's needs; this ingredient is also well tolerated at these levels.

Learn more about Dimethyl Isosorbide

Hydroxypinacolone Retinoate

Skin Conditioning

Hydroxypinacolone Retinoate (aka Granactive Retinoid or HPR) is a retinoid that is part of the same vitamin A family as retinol.

It is an ester of retinoic acid that binds directly to your skin's retinoic acid receptors so it doesn't need your skin to convert it through several steps before it can do anything.

In practice, this means it does the classic retinoid jobs in a formula:

The best part is that it can do all this with noticeably less redness, flaking, and stinging than traditional retinoids.

That gentle reputation is backed by lab work as well; a 2018 study on skin models found that HPR triggered higher retinoid-gene activity than retinol, retinal, or retinyl propionate at the same concentrations while being less irritating to cells.

It also boosted procollagen production to levels similar to retinoic acid itself.

A 2023 study showed HPR works synergistically with retinyl propionate to switch on collagen-building pathways and a 2025 clinical serum study in women with mild photoaging saw improvements in wrinkles and elasticity (though that formula also contained retinol, peptides, and Silybin).

One naming quirk worth mentioning:

You'll likely see this ingredient sold under the trade name "Granactive Retinoid", which is actually only 10% HPR blended with 90% Dimethyl Isosorbide solvent. This means a 5% Granactive Retinoid really only means about 0.5% HPR.

Finished products typically land somewhere between 0.05-1% and it's happiest formulated at a mildly acidic to neutral pH (~5.5-6.5).

Another perk is that this is one of the more light- and temperature-stable retinoids which is a nice bonus for shelf life.

Learn more about Hydroxypinacolone Retinoate