Goji berries (Lycium barbarum) are a good source of vitamin C, potassium, carbohydrates, and phosphorus. The fruit has a citrus flavor.
Pre-clinical and clinical researches suggest lycium fruit may have anti-aging, anti-tumor, cyto-protective, immunomodulatory, and neuro-protective effects. It also may have benefits for fatigue/endurance, general well-being, glaucoma, glucose control in diabetes, and metabolism/energy expenditure. Recently, the juice of lycium fruit has become popular as an antioxidant-rich tonifier.
According to Roy Upton, president of AHP (American Herbal Pharmacopoeia), in the past few years, lycium fruit has transitioned from relative obscurity in the United States to being integrated into commercial cereals, bulk food products, candies, and juice products. Its growth and popularity have been exponential, but many people are still unaware of the myriad of benefits associated with its consumption.
In addition to high amounts of the super antioxidant vitamin C, goji has an ORAC value (oxygen radical absorbance capacity) of 140,000 (μ mol TE/100g) making it one of the richest antioxidant fruits compared with many other fruits and superfuits.
The neurological protective effect of goji berries has been demonstrated in an experimental study including human clinical trial. Glutamate has been shown to be excitotoxic and is being implicated in many neurodegenerative diseases including Parkinson’s disease and Alzheimer’s disease [61, 72]. Thus, reduction of glutamate toxicity is considered a therapeutic strategy for those neurodegenerative diseases. 
Everyday stress, pollution and processed foods can lead to the formation of free radicals. The antioxidants found in goji berries can literally mop up these free radicals, protecting the body from their damage.
A study published in the Journal of Alternative and Complementary Medicine found that volunteers who drank goji berry juice daily for two weeks reported increased energy levels, improved athletic performance, better focus, and mental sharpness. 
Calmness & Mental Benefits
The same study reported quality of sleep, ease of awakening, ability to focus on activities, mental acuity, calmness, and feelings of health, contentment, and happiness.
Neurologic/psychologic performance and gastrointestinal functions also improved.
Age-related macular degeneration (AMD) is a common disorder that causes irreversible loss of central vision. Increased intake of foods containing lutein and zeaxanthin may be effective in preventing AMD. , 
15 g of goji berries per day is considered beneficial to supply adequate zeaxanthin which is estimated at 3 mg/day as a dietary supplement for eye health. 
Patients who experienced interactions between goji berries and warfarin have been described in three published case reports. Warfarin is prescribed as a common anti-coagulation therapy. Always consult with your physician before taking any supplements which could inter-act with any medication.