What's in the plant, what substances does it have?
Fo Ti contains a number of compounds, including stilbene glucosides, anthraquinone glucosides and anthraquinone derivates.

Benefits of this herb
Fo Ti has several properties, including the ability to lower triglyceride levels and can also act as a good antioxidant. Studies in rodents indicate Fo-Ti can enhance memory. Does it work for hair growth? We have not seen human studies yet that show this benefit.

Antioxidant
The radical scavenging effects of stilbene glucosides from Polygonum multiflorum.
Arch Pharm Res. 2002.
The extract of the root of Polygonum multiflorum exhibited a significant antioxidant activity assessed by the DPPH radical scavenging activity in vitro. The bioassay-guided fractionation of the extract yielded a stilbene glucoside, as an active constituent responsible for the antioxidant property. Compound 1 demonstrated a moderate DPPH radical scavenging activity, while the corresponding deglucosylated stilbene 2 exhibited a much higher activity.

Aphrodisiac Properties
Fo Ti is sometimes claimed to be a sex enhancer and found in some sex pill products. We have not come across any studies regarding this property of Fo Ti as a use for improving low sex drive. We are not aware of specific human studies regarding the role of fo-ti herb in erectile dysfunction as of January 2009.

Brain and memory
Changes in hippocampal synapses and learning-memory abilities in age-increasing rats and effects of tetrahydroxystilbene glucoside in aged rats.
Neuroscience. 2007.
The aim of the present study is to investigate the changes in hippocampal synapses and their relation with learning-memory abilities at different ages, and evaluate the effects of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside (TSG), which is one of the major components of a traditional Chinese herb Polygonum multiflorum Fo Ti, on brain aging. In conclusion, hippocampal synapses count and synaptophysin expression decreased in aged rats, which may be one of the mechanisms involved in learning-memory deficit. TSG reversed the above changes in aged rats, suggesting that TSG may be beneficial for the treatment of Alzheimer disease or cognitive impairment in old people.

Beneficial effects of different Polygonum multiflorum Thunb (Fo-Ti) extracts on memory and hippocampus morphology.
J Nutr Sci Vitaminol 2002.
Four groups of 1-mo-old male senescence-accelerated mice (SAMP8) were fed Fo-Ti extract for 18 wk to determine the effect of PM on memory ability and histopathological changes in mice. The baseline diet consisted of a casein diet group, and the three test diets were supplemented with 50% ethanol, 95% ethanol, or water extracts of Fo-Ti. It was found that the mice fed with Fo-Ti extracts had better active shuttle avoidance response, fewer vacuole numbers, less lipofuscin in the hippocampus, and lower MDA concentrations in the brain. Our data showed that the ethanol Fo-Ti extract groups (both 50% and 95% groups) had lower lipofuscin percentages and MDA concentrations, and higher total thiol concentrations than the water PM extract group. The 50% ethanol Fo-Ti extract group showed significantly lower total cholesterol and triglyceride values than the other groups, but the HDL cholesterol level was the same. These results suggest that dietary supplementation with either ethanol or water extracts can reduce brain pathological changes and promote learning and memory ability. The performance of Fo-Ti extracts depended on the extraction method, with ethanol extraction tending to obtain better results.

Protective effect of polygonum multiflorum thunb on the cerebral cholinergic neurofibers in rats
Hunan Yi Ke Da Xue Xue Bao. 2003.
Excitative neurotoxin kainic acid was injected into the basal forebrain, Meynert neucleus, medial septal neucleus and the Broca neucleus to establish the destruction model. Then the destructive experimental group was fed with Fo-Ti, and the histochemical method was used to display the changes of AChE fibers, the protection and activation of Fo-Ti. The number of projecting AChE fibers to the cortex and the hippocampus in PMT group was larger than that in the control group, and no morphological destruction was seen in the experimental group. Fo-Ti has a protective effect on AchE projecting fibers in rats.

Colitis, inflammatory bowel disease
Protective effects of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside, an active component of Polygonum multiflorum, on experimental colitis in mice.
Eur J Pharmacol. 2007.
Reactive oxygen metabolites and inducible nitric oxide synthase (iNOS) are involved in pathogenesis of inflammatory bowel disease. In this study, we examined the effects of 2,3,5,4'-tetrahydroxystilbene-2-O-beta-d-glucoside (THSG), an active component extracted from Fo Ti, on acetic acid-induced acute colitis and mitomycin C-induced chronic colitis. We find that THSG exerts protective effects on experimental colitis through alleviating oxygen and nitrogen free radicals level and down-regulating iNOS expression.

Use for hair loss
Although this herb is commonly used for this purpose, we have not seen clinical trials that show it to be effective in reversing hair loss.