Recommended by holistic veterinarians, Herbsmith Rx Rehmannia Tonify Yin is a Traditional Chinese Veterinary Medicine (TCVM) herbal formula that tonifies Kidney and Liver Yin to support Yin-Yang balance in the equine athlete. When horses are pushed through active show schedules, competition, or sustained training demands, Yin becomes gradually depleted, manifesting as generalized weakness, especially in the lower back and limbs. This formula replenishes Yin, restoring the foundation that sustains athletic performance and overall health. Available in traditional powder (500g, 900g, 1200g) and Flax Plus (30-day and 60-day supply); the Flax Plus format includes a six-tablespoon scoop. Dosing varies by body weight and health condition; your authorizing veterinarian will provide specific guidance. Suitable for long-term use.
VETERINARY AUTHORIZATION REQUIRED: Submit Your Authorization Request or Request a TCVM Telemedicine Consultation
What It Supports
- Yin tonification for the athletic horse: Replenishes Kidney and Liver Yin depleted by sustained athletic demands, competition stress, and the inherently Yang nature of performance horses.
- Hind limb and lower back strength: Addresses Kidney Yin deficiency patterns that manifest as skeletal weakness, particularly in the lower back and legs, helping restore structural support for athletic movement.
- Heat clearing and Blood nourishment: Addresses Liver Yin deficiency, which affects the Blood and generates internal heat; supports healthy Blood quality and a calm, balanced internal environment.
- Fatigue management and performance maintenance: Supports the Yin foundation that sustains long-term Yang activity, helping performance horses maintain vitality and competitive readiness across an active show schedule.
TCVM Principles
- Primary action: Tonify Kidney and Liver Yin, support Yin-Yang balance, nourish the Blood, and clear deficiency Heat.
- Approach: In TCVM, Yang is outward, active, and athletic in nature; Yin is inward, restorative, and fluid in nature. The athletic horse is inherently Yang-dominant, and sustained performance gradually depletes Yin. Kidney Yin deficiency leads to skeletal weakness, especially in the lower back and legs; Liver Yin deficiency affects Blood quality and generates internal heat. Long-term Yin deficiency causes fatigue and increased susceptibility to dysfunction. This six-herb classical formula (based on Liu Wei Di Huang Wan) directly replenishes Yin while clearing deficiency Heat, providing the restorative foundation the athletic horse needs to sustain peak performance. Suitable for long-term use.
Available Forms
- 500g Traditional Powder: Mix into grain twice daily for the first 20 days, then once daily. If the horse is reluctant to eat herbs, begin with small amounts in grain to acquaint the horse with the taste, or consider the Flax Plus version.
- 900g Traditional Powder: Larger supply for ongoing long-term use or multi-horse households.
- 1200g Traditional Powder: Bulk size for extended, consistent daily administration.
- Flax Plus - 30-Day Supply: Herbal formula blended with ground flaxseed for easy administration; includes a six-tablespoon scoop. Administer one scoop twice daily for the first 20 days, then one scoop daily.
- Flax Plus - 60-Day Supply: Extended Flax Plus supply for continued long-term daily use.
Ingredients
Active ingredients: Shu Di Huang (Rehmannia glutinosa preparata) - Cooked Rehmannia root; Shan Zhu Yu (Cornus officinalis) - Cornus fruit; Shan Yao (Dioscorea opposita) - Chinese yam; Fu Ling (Poria cocos) - Poria; Mu Dan Pi (Paeonia suffruticosa) - Moutan bark; Ze Xie (Alisma orientale) - Alisma tuber.
Inactive ingredients (Flax Plus only): Ground Flax Seed. Traditional Powder contains no inactive ingredients.
VETERINARY AUTHORIZATION REQUIRED: Submit Your Authorization Request or Request a TCVM Telemedicine Consultation
Active Ingredient TCVM Actions
Rehmannia Tonify Yin is based on the classical Liu Wei Di Huang Wan (Six Ingredient Rehmannia Pill), one of the most celebrated Yin-tonifying formulas in Chinese medicine, structured around three tonifying herbs and three draining herbs for balanced, sustained Yin replenishment:
- Shu Di Huang (Rehmannia glutinosa preparata) - Cooked Rehmannia root: The chief herb; the primary Yin and Blood tonic of the formula. Tonifies Kidney and Liver Yin, nourishes Blood and Essence, and provides the primary Yin-replenishing action that addresses the root deficiency pattern in the athletic horse.
- Shan Zhu Yu (Cornus officinalis) - Cornus fruit: Tonifies and stabilizes Kidney and Liver Yin, astringes Essence to prevent further Yin leakage, and supports the Kidney's holding function; complements Shu Di Huang in nourishing Yin from both the Kidney and Liver channels.
- Shan Yao (Dioscorea opposita) - Chinese yam: Tonifies the Spleen and Stomach to support Qi production and Yin generation from food; ensures the formula has a digestive foundation so the Yin-tonifying herbs are well absorbed and utilized.
- Fu Ling (Poria cocos) - Poria: Strengthens the Spleen, resolves Dampness, and gently drains; counterbalances the heavy, cloying nature of Shu Di Huang to prevent the formula from becoming stagnating and to support smooth Qi and fluid movement.
- Mu Dan Pi (Paeonia suffruticosa) - Moutan bark: Clears deficiency Heat generated by Liver Yin deficiency, cools the Blood, and resolves Blood stasis; addresses the Heat component of Liver Yin deficiency that affects Blood quality and generates internal warmth.
- Ze Xie (Alisma orientale) - Alisma tuber: Drains Kidney Fire and Dampness, prevents Kidney Yin stagnation, and supports healthy fluid metabolism; the classical counterbalance to Shu Di Huang, ensuring the formula tonifies without creating internal congestion.
Potential Drug Interactions
Herbsmith Rx Rehmannia Tonify Yin contains Yin-tonifying, Blood-nourishing, and Heat-clearing herbs that may interact with certain medications. Horses on prescription medications should use this formula under veterinary supervision, as herb-drug interaction research in horses remains limited.
Medication categories warranting extra caution include anticoagulant or antiplatelet medications (Shu Di Huang and Mu Dan Pi have Blood-moving properties that may have additive effects), diuretics or medications affecting fluid and electrolyte balance (Ze Xie has mild diuretic properties), immunosuppressive drugs or corticosteroids, and horses managing multiple concurrent prescriptions. Your veterinarian can determine appropriateness based on your horse's condition, current medications, and laboratory results.
VETERINARY AUTHORIZATION REQUIRED: Submit Your Authorization Request or Request a TCVM Telemedicine Consultation
Frequently Asked Questions
What is Rehmannia Tonify Yin used for in horses?
Rehmannia Tonify Yin is most commonly recommended for performance and competition horses showing TCVM signs of Kidney and Liver Yin deficiency: generalized weakness, especially in the lower back and limbs; fatigue that develops over an active show season; internal heat signs; or difficulty maintaining vitality across sustained athletic demands. It is an excellent long-term support formula for horses whose Yang-dominant athletic lifestyle gradually depletes their Yin foundation.
How is Rehmannia Tonify Yin administered, and what are the recommended doses for a 1,000 lb horse?
For the traditional powder, administer two tablespoons twice daily for the first 20 days, then two tablespoons once daily. For the Flax Plus format, administer one scoop (six-tablespoon scoop included) twice daily for the first 20 days, then one scoop daily. Mix into grain for easy administration. If the horse is reluctant to eat the herbs, begin with small amounts in grain and gradually increase, or choose the Flax Plus version. Confirm dosing for horses of other weights with your authorizing veterinarian.
How long does it take to see results, and can this formula be used long-term?
Yin tonification is a gradual process; most horse owners begin to notice meaningful improvements in vitality, hind limb strength, and overall resilience within 3 to 6 weeks of consistent use. Unlike warming or stimulating formulas, Rehmannia Tonify Yin is suitable for long-term use and can be taken continuously as part of an athletic horse's ongoing health maintenance protocol. It is also an excellent follow-on formula after completing a course of Herbsmith Codonopsis Support Energy.
Can Rehmannia Tonify Yin be used alongside other Herbsmith formulas?
Yes. Herbsmith specifically recommends Rehmannia Tonify Yin as a follow-on formula after Herbsmith Codonopsis Support Energy to sustain and prolong the energy gains achieved. The Flax Plus format combines the herbal formula with ground flaxseed, adding Omega-3 support for joints, coat, and cardiovascular health in a single daily feeding. When combining with other supplements or prescription medications, always consult your authorizing veterinarian to confirm compatibility with your horse's full health protocol.