Petroleum jelly is not considered bad for you when used as intended on the skin. High-quality, refined products are generally safe, non-irritating, and rarely cause allergic reactions.
It works by forming a protective barrier over the skin, helping to lock in moisture and support healing. Studies show it can improve the skin barrier and even support natural defenses, which is why it is commonly used for dry skin, minor wounds, and irritation. It is also considered noncomedogenic in most cases, meaning it does not typically clog pores.
That said, safety depends on how it is used. Problems have been reported when petroleum jelly is applied inside the nose over long periods, as it can be inhaled and affect the lungs. There are also concerns about certain impurities in poorly refined products, although regulated medical and cosmetic versions are purified to reduce this risk.
For everyday use, apply a thin layer to clean skin and avoid using it inside the nose or inhaling it. If you have persistent skin issues or concerns about reactions, it is best to consult a dermatologist before continued use.