Rosehip oil or rose hip seed oil is extracted from the 'hips' (fruit) of the rose. The hips are the small berry like fruit that's left once the roses have bloomed and lost their petals.
It is entirely different in chemical compounds and aroma to rose flower oil. Rosehip oil is usually harvested from Rose Moschata, Rosa Rubignosa or Rosa Canina varietals. This is in contrast to rose flower oil which is widely derived from Rosa Damascena or Rosa Centifolia.
Rosehip oil contains transretinoic acid (up to 0.357ml/L), tannins, flavonoids, vitamin C and β- carotene . Transretinoic acid (tretinoin) is the pre cursor for a potent and effective form of Vitamin A. This natural retinoid ( Vitamin A ) stimulates the dermis where collagen, elastin and blood vessels reside thereby helping reducing dark spots and wrinkles. Vitamin A is
Bear in mind that Vitamin A breaks down and deteriorate when exposed to air and light so any formulation containing a high content Vitamin A is best used at night. If used in the day time, be vigilant about using a good sun block.
Rosehip oil is often touted as being rich in Vitamin C. However it is the hip or the fruit that is rich in Vitamin C, not the oil itself. Most of the Vitamin C is destroyed in the extraction process. Vitamin C is also water as opposed to lipid soluble. Certain rosehip oil formulations contain added Vitamin C from alternative sources.
The oil is primarily composed of essential saturated and unsaturated fatty acids. It contains Linoleic acid (41%-50%), linolenic acid (26%-37%), Oleic acid (10%-20%), palmitic acid (3%-5%), stearic acid (1%-3%).
These fatty acids; particularly linoleic acid are an important component of cell membranes and is the key reason behind the regenerating, wrinkle and scar reducing qualities of rosehip oil.
The high content of linoleic acid can cause it oxidise or go rancid quickly which explains why most formulations with rosehip oil also contain antioxidants like Vitamin E to extend the shelf life.
Linoleic acid is ideal for acne prone skin. Skin prone to acne out break outs have a higher percentage of oleic acid in the sebum. Rosehip oil has a higher ratio linoleic acid to oleic acid thus making it a lighter, non greasy, non comedogenic skin serum.