Rehmannia root powder has been used to enhance energy. This plant is native to China, Japan, and Korea. Traditionally, the root has been used to replenish vitality, strengthen the liver, kidney, and heart, and for treatment of a variety of ailments like diabetes, anemia, and urinary tract problems. This herb is sometimes included in sexual enhancement products.

Studies and benefits
Rehmannia glutinosa has been shown to help maintain healthy blood sugar levels.
Is involved in red blood cell regeneration.
May be involved in anti tumor activity.
Rehmannia is used to enhance energy and sexuality, and it could also have benefits in terms of blood sugar control. In China, it has been used for certain hearing problems and for kidney disease.

Kidney disease
Rehmannia glutinosa ameliorates the progressive renal failure induced by 5/6 nephrectomy.
J Ethnopharmacol. 2009.
In this study, we evaluated the renoprotective effect of aqueous extract of Rehmannia glutinosa in progressive renal failure. Rehmannia glutinosa reduced the serum creatinine level, 24-h urinary protein excretion, and glomerulosclerosis, and it also inhibited the expression of angiotensin II, AT(1) receptor, TGF-beta1 and type IV collagen in the renal cortex. These results suggest that the renoprotective effect might be mediated by suppressing the expression of angiotensin II and AT(1) receptor and by regulating TGF-beta1 and type IV collagen expression.

Blood sugar control, diabetes
Hypoglycemic effect of rehmannia glutinosa oligosaccharide in hyperglycemic and alloxan-induced diabetic rats and its mechanism.
J Ethnopharmacol. 2004.
The hypoglycemic and anti-diabetic effect of Rehmannia glutinosa oligosaccharide in glucose-induced hyperglycemic and alloxan-induced diabetic rats and its mechanism was investigated. It was found that pretreatment of rehmannia in normal rats induced a partial prevention of hyperglycemia caused by glucose, while when hyperglycemia was induced in adrenalectomized rats, the preventive effect of rehmannia on hyperglycemia was lost. The results indicated that this oligosaccharide exerts a significant hypoglycemic effect in normal and alloxan-induced diabetic rats.

Characterization of the anti-diabetic and antioxidant effects of rehmannia glutinosa in streptozotocin-induced diabetic wistar rats.
Am J Chin Med. 2008.
This study investigated the effects of Rehmannia glutinosa individually as well as in combination with the oral hypoglycemic agent, metformin in streptozotocin (STZ)-induced diabetic Wistar rats. The diabetic rats were divided into the following groups (each n = 6) and received the respective treatments for 30 days: (1) metformin (500 mg/kg), (2) Rehmannia glutinosa (200 mg/kg), (3) metformin (500 mg/kg) and RG (200 mg/kg) and (4) diabetic control. A reduction in plasma glucose levels caused by the herb was not as significant as metformin compared to the diabetic control. However, Rehmannia glutinosa-treated group showed reductions in plasma C-reactive protein (CRP) levels compared to the diabetic controls as well as metformin-treated group. An enhanced reduction in CRP concentration was observed in the group receiving both herb and metformin compared to metformin-treated group. Reduction in CRP levels suggests an anti-inflammatory activity of the herb.

Passion Rx for sexual enhancement in a male and female, works within 2 to 3 days
Passion Rx provides results that are often seen within two to four days, but continue to improve with use. Various doses and extracts of dozens of herbs from a number or raw material suppliers have been evaluated to determine the ideal dosage and combination for optimal aphrodisiac properties with the fewest side effects. After years of trial and error, a unique proprietary blend with more than a dozen herbal extracts from the best raw material suppliers has been created. The exact dosage and herbal extract potencies of this effective aphrodisiac blend is a close kept secret only known to the doctor and his research staff.

Renowned physician and herbal expert Dr. Ray Sahelian, M.D., author of Natural Sex Boosters, has discovered a combination of exotic herbs from the Amazon jungle, India, China, Malaysia, and Africa, that support healthy desire and performance, as well as to simply enhance sexual pleasure. The potent herbal extracts include Ashwagandha, Aspallum purificata, Catuaba, Cnidium, Coleus forskohlii, Damiana herb, DMAE, Horny goat weed herb, Maca herb, Mucuna pruriens, Muira puama, Passion flower, Rehmannia, Rhodiola, Tribulus, LJ100 and Tongkat Ali herbal extract from Asia.

What's in rehmannia glutinosa herb?
From the extract of dry roots of rehmannia glutimosa, fatty acids, palmitic acid, beta-sitosterol, daucosterol, sulfur cyclic cerebroside, dammelittoside, melittoside, rehmaglitin, alpha-Galactosidase and beta-glucosidase, bis-furan derivatives have been isolated. See a list of Chinese Herbs. This herb has rehmapicroside, norcarotenoids, 2-formyl-5-hydroxy-methylfurane, the iridoid rehmaglutin D, iridoid glycosides, and phenylethyl alcohol glycosides.

Hearing conditions
Rehmannia glutinosa activates intracellular antioxidant enzyme systems in mouse auditory cells.
Am J Chin Med. 2006. Department of Food and Nutrition, Kunsan National University, South Korea.
Steamed roots of rehmannia glutinosa have been traditionally used in Oriental medicine for the treatment of auditory diseases such as tinnitus and hearing loss. To investigate whether the ethanol extract of steamed roots of Rehmannia glutinosa increases activity of antioxidant enzymes and the level of glutathione (GSH), we measured activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and glutathione reductase and GSH level in HEI-OC1 cells after treatment with rehmannia glutinosa. The SOD and CAT activities were significantly increased in the presence of Rehmannia glutinosa compared to the control group. The GPX activity also increased dramatically in response to the treatment with rehmannia glutinosa in a dose-dependent manner.  The level of GSH gradually increased in the presence of rehmannia glutinosa. In the cytotoxicity test, 5-50 microg/ml of rehmannia glutinosa did not show any significant cytotoxicity. These results suggest that the traditional use of rehmannia glutinosa for the treatment of auditory diseases may be explained, in part, by activation of intracellular antioxidant enzyme systems.

Protective effect of Rehmannia glutinosa on the cisplatin-induced damage of HEI-OC1 auditory cells through scavenging free radicals.
J Ethnopharmacology. 2006. Department of Food and Nutrition, Kunsan National University, Kunsan, South Korea.
The steamed root of rehmannia glutinosa has been used in traditional Oriental Medicine for treatment of inner ear diseases, such as tinnitus and hearing loss. In the present study, we showed that the ethanol extract of steamed roots of rehmannia glutinosa protected HEI-OC1 auditory cells from cisplatin cytotoxicity in a dose-dependent fashion.

Rehmannia research, osteoporosis
J Diabetes. 2011. Review of the effects of the traditional Chinese medicine Rehmannia Six Formula on diabetes mellitus and its complications. Rehmannia Six Formula (RF) is a formula that is commonly used in Traditional Chinese Medicine to treat patients with diabetes. A literature search was performed in PubMed for the years 2000-2009 using the key words RF, Rehmannia glutinosa, Fructus Corni, Dioscorea sp. (D. alata, D. opposita, D. batatas), Poria cocos, Alisma sp. (A. orientalis, A. plantago aquatica), and Paeonia suffruticosa/Cortex Moutan. On the basis of the publications found, RF appears to have beneficial effects on blood glucose, neuropathy, and nephropathy.

Molecules. 2013. Dried root of Rehmannia glutinosa prevents bone loss in ovariectomized rats.

Q. I found information on that web that said Rehmannia Rutinosa in a study to improve bone density. The article also said something about Rehmannia root powder and extract. Is there more studies being done on this? I am 57 years old and have had osteopenia since I was 40 years old. Somehow 3 years went by and my latest done density scan showed osteoporosis in my scrum not the hip yet. Can I be included if you are doing another study? I do not want to take Fosamax because I have severe bone loss in my mouth and have had some TMJ before.
   A. I am not aware of human studies yet with the use of this herb for bone density.

Liver cancer
Hot water-extracted Lycium barbarum and Rehmannia glutinosa inhibit proliferation and induce apoptosis of hepatocellular carcinoma cells.
World J Gastroenterol. 2006.
To investigate the effect of hot water-extracted Lycium barbarum and Rehmannia glutinosa on cell proliferation and apoptosis in rat and/or human hepatocellular carcinoma (HCC) cells. Hot water-extracted crude lycium barbarum and rehmannia glutinosa inhibit proliferation and stimulate p53-mediated apoptosis in HCC cells.

Brain, memory
Effect of radix Rehmanniae preparata on the expression of c-fos and NGF in hippocampi and learning and memory in rats with damaged thalamic arcuate nucleus
Zhong Yao Cai. 2004.
To study the effect on improving the function of learning and memory.  Rehmannia could improve the function of learning and memory of MSG rats, and its mechanism may by related with the increase of the expression of hippocampal c-fos and NGF.

Evaluation of natural products on inhibition of inducible cyclooxygenase (COX-2) and nitric oxide synthase (iNOS) in cultured mouse macrophage cells.
J Ethnopharmacol. 2002.
The inhibitors of prostaglandin biosynthesis and nitric oxide production have been considered as potential anti-inflammatory and cancer chemopreventive agents. In this study, we evaluated approximately 170 methanol extracts of natural products including Korean herbal medicines for the inhibition of prostaglandin E(2) production (for COX-2 inhibitors) and nitric oxide formation (for iNOS inhibitors) in lipopolysaccharide (LPS)-induced mouse macrophages RAW264.7 cells. As a result, several extracts such as Aristolochia debilis, Cinnamomum cassia, Cinnamomum loureirii, Curcuma zedoaria, Eugenia caryophyllata, Pterocarpus santalius, Rehmannia glutinosa and Tribulus terrestris showed potent inhibition of COX-2 activity (>80% inhibition at the test concentration of 10 micro g/ml). In addition, the extracts of A. debilis, Caesalpinia sappan, Curcuma longa, C. zedoaria, Daphne genkwa and Morus alba were also considered as potential inhibitors of iNOS activity (>70% inhibition at the test concentration of 10 micro g/ml). These active extracts mediating COX-2 and iNOS inhibitory activities are warranted for further elucidation of active principles for development of new cancer chemopreventive and/or anti-inflammatory agents.

Questions
I have been diagnosed with cochlear Meniere's and am not sure which product I should be taking. I read about the rehmannia for hearing conditions and the rehmannia glutinosa that activates. Does it matter which one I take? Rehmannia Endurance or Passion Rx? Would one be better than the other for my condition??
   Passion Rx is recommended for sexual enhancement, not hearing problems. We don't have clinical experience with rehmannia, we just listed the study we came across but don't know if it will be effective. You may ask your doctor if it is appropriate for you. Please keep us updated.

Q. Does rehmannia thin blood or thicken blood? My blood is too thick. I am interested in a sexual enhancer than contains rehmannia. Being 69 years old, there is a problem with erectile dysfunction.
   A. Passion Rx has rehmannia and several other herbs and we don't know how the whole combination influences blood thinning.

Rehmannia Endurance, 637 mg, 150 Tabs
Planetary Formulas Rehmannia Endurance is based on the classic Chinese tonifer Rehmannia Six: Liu Wei Di Huang Wan, one of the most strengthening tonics of Chinese herbalism. Traditionally it was used for those who are tired and run down from overwork and inadequate rest due to a fast paced-lifestyle.

Supplement Facts:
Calcium - 128 mg - 15%DV
Rehmannia Root - 320 mg
Poria Cocos Sclerotium - 160 mg
Tree Peony Root Bark - 160 mg
Dioscorea Root - 160 mg
Alisma Rhizome - 160 mg
He Shou Wu Root (Fo Ti) - 80 mg
Chrysanthemum Flower - 64 mg
Ligustrum Seed - 64 mg
Saw Palmetto Berry - 48 mg
Lycii Fruit Extract - 40 mg
Cornus Fruit - 18 mg

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Shu Di Huang rehmannia 
Saeng Ji Hwang has a protective effect on adriamycin-induced cytotoxicity in cardiac muscle cells.
Life Sci. 2005. Department of Pharmacology and Institute of Cardiovascular Research, School of Medicine, Chonbuk National University, Jeonju, Republic of Korea.
This study examined the effect of Saeng Ji Hwang (Radix Rehmanniae) on cardiac muscle cells. Overall, the results suggest that Saeng Ji Hwang -associated Mn-SOD and GSH are important factors in the mechanism of the Saeng Ji Hwang -induced protective mechanism in H9C2 cardiac muscle cells.