Goji Berry

What is goji berry?

Goji berries are the small red fruits of Lycium barbarum and the closely related Lycium chinense, shrubs long used as both food and medicine in China, where the dried fruit is called gou qi zi. In English they are also known as wolfberries. “Goji” is a fairly new marketing name; the berries became popular in Western health food stores in the early 2000s, sold dried, as juice and as powdered extracts.

The fruit contains a group of complex carbohydrates bound to proteins, usually called Lycium barbarum polysaccharides (LBP), along with carotenoids, especially zeaxanthin, plus vitamin C and other antioxidants. A review in Planta Medica noted that most pharmacological research has focused on these polysaccharides, which showed antioxidant activity and effects relevant to aging in laboratory studies (Potterat, 2010).

What the research says

Brain and memory

Supplement marketing often calls goji “neuroprotective.” That idea comes mostly from animal and cell research on LBP, which has looked at oxidative stress, inflammation and models of cognitive decline in rodents. These studies are useful for generating hypotheses, but they do not show that eating goji or taking an extract improves memory in people. We did not find a controlled human trial testing goji for memory as a primary outcome.

Well-being and energy

The most-cited human trial gave 120 mL a day of a standardized goji juice or placebo to 34 healthy adults for 14 days. The goji group reported better ratings for energy, sleep, focus, calmness and digestion, while the placebo group reported few changes (Amagase and Nance, 2008). The study was small and short, relied on self-rated questionnaires and was run by the company that made the juice, so the results are best treated as preliminary.

Eye health

The clearest human signal is for the eyes. In a 90-day randomized pilot trial of 27 adults aged 45 to 65, eating 28 grams of whole dried goji berries five times a week increased macular pigment optical density, a marker linked to eye health, while a lutein and zeaxanthin supplement did not (Li et al., 2021). This fits goji’s high zeaxanthin content, but the study was small and unmasked.

How it’s used in supplements

Goji appears in supplements as dried fruit powder, juice concentrate or an extract standardized to a percentage of polysaccharides. Studies have used quite different amounts, from 120 mL of juice to 28 grams of whole berries, so there is no established supplement dose. In multi-ingredient brain formulas it is often included for its antioxidant profile, frequently in amounts that are not disclosed.

Safety

Goji eaten as food is generally well tolerated. The main known risk is an interaction with warfarin: case reports describe people whose INR rose sharply and who had bleeding after drinking goji juice or tea while on warfarin (Rivera et al., 2012). Anyone taking a blood thinner should talk with their doctor before using goji products. People with diabetes or high blood pressure who take medication should also check first, and allergic reactions have been reported. Safety in pregnancy and breastfeeding has not been well studied.