Rosa canina fruits (often known as rose hip) have been used in herbal remedies since ancient times. On the basis of anecdotal reports about the effects of rose hip preparations on human health and citations to the same in ancient texts, in vitro and in vivo studies have been conducted that have made it possible to learn about some active ingredients in rose hip, as well as how the component compounds might exert their effects. From such studies, it has been documented that there is a great variation in active ingredients when comparing different rose hip products. Factors which affect the quality and quantity of active ingredients in the rose hip products include the subspecies of the particular R. canina from which the fruits are harvested, the environment during plant growth, time of harvesting, and the amount of seeds and shells/husks incorporated into the preparation. Studies in animals and in humans are of great importance for determining the true bio-effects of rose hip. Such in vivo studies that have only been performed during the last 2 decades indicate that the treatment of patients with different types of joint disease with rose hip powder based on a subspecies of R. canina (Lito) containing a certain galactolipid (GOPO) can alleviate pain, improve daily activity, and even reduce the consumption of regular pain relievers. As several rose hip components have been shown to be anti-inflammatory, it is suggested that anti-inflammatory mechanisms might explain some reductions in symptoms associated with administering rose hip to arthritic conditions. Although the number of publications of randomized and placebo-controlled clinic studies with rose hip is small, the overriding evidence is that the anti-inflammatory effects from administration of rose hip preparations containing both shells and seeds are superior to preparations containing shells alone.