Ah, brown spots, . . . some are beautiful, some are not. Some are inherited, like freckles, others are caused by irritation, friction or injury on the skin (this could be as simple as a pimple). Some are caused by hormonal, or drug, stimulation of the cells that make melanin, and some are pigmentation marks referred to as photo-aging, which are the tell-tale signs of sun exposure during a lifetime.
Hyperpigmentation is triggered by an enzyme that blocks the production of melanin causing an oxidation reaction much like the blackening of a potato, or avocado, when exposed to air.
No matter the cause, there are two approaches to lightening hyperpigmentation. Skin bleaching and skin lightening. The only skin bleaching agent the FDA acknowledges is hydroquinone which gives fairly rapid results, but unfortunately they are short lived. Darker pigmented cells will surface when the lightened ones shed.
Skin lightening products and light therapy can offer longer lasting improvements, although the results may take a little longer (approximately 28 days). They are more efficient and much easier on the skin. A good exfoliation routine will allow for better penetration of the ingredients being applied. No matter the type of pigmentation you want to treat, sun exposure is counterproductive, so make sure to wear sun protection and/or avoid UV exposure.
Coming up . . . reviews of skin lighteners.