Bio-Oil is a brand that develops and sells specialist skincare products using oil to improve the appearance of scars, stretch marks, dry skin, and other skin concerns. It was developed to help prevent and heal scars and stretch marks.
The ingredients of Bio-Oil include:

Mineral oil
Sunflower seed oil
Tocopheryl acetate (vitamin E)
Anthemis nobilis flower (chamomile) oil
Lavandula angustifolia (lavender) oil
Rosmarinus officinalis (rosemary) oil
Calendula officinalis (marigold) extract
Glycine soja (soybean) oil

Bio-Oil claims to help:

Improve the appearance of new and old scars
Improve the appearance of stretch marks
Improve the appearance of hyperpigmentation (uneven skin tone) for both dark and light skin types
Smooth and tone aging skin on the face and body
Retain skin moisture

According to a 2018 study of 80 people with non-hypertrophic scars, Bio-Oil showed a 14 percent better reduction in scarring and striae (stretch marks) in comparison with an untreated area.
Although Bio-Oil is generally considered safe, it isn?t recommended for use on broken or bleeding skin. Also, according to a 2016 study, a fragrance ingredient in Bio-Oil, linalool, is a known allergen. If you think you might be sensitive to linalool or any of the listed ingredients in Bio-Oil, before starting regular use, put a small amount on your forearm and wait 30 to 60 minutes. If you experience a reaction, discontinue use