Key Takeaways
- Overall score: 7.2 / 10 — The second-highest-scoring Hoof Health product in our database, behind only Horseshoer’s Secret Extra Strength (7.8). At $1.43/day versus the Extra Strength’s $2.53/day, the original formula is the value pick of the two.
- One of only four Hoof Health products in our database to earn a Recommended badge, and the cheapest of that group with the most complete four-nutrient panel (biotin, zinc, copper, methionine).
- Biotin at 15 mg is the structural gap, 25% below the 20 mg consensus target that Extra Strength and Farrier’s Formula DS both hit. For horses with active hoof cracks, this shortfall is a reason to add a standalone biotin top-up rather than switch products.
- Methionine at 2,724 mg per serving (109% of threshold) is the single highest methionine dose in our Hoof Health database. No other audited product exceeds the methionine target.
- Quality Assurance scores 7/15, tied with Extra Strength for the highest QA score in Hoof Health. NASC Quality Seal membership since 2002 is what earns it. Most Hoof Health products score 0-2 on this dimension.
Label Transparency — 14 / 15
Farnam publishes a full Guaranteed Analysis that quantifies every ingredient that matters for hoof health. Biotin is listed as a minimum of 40 mg/lb, which works out to 15 mg per 6 oz scoop. Zinc and copper are given in ppm (1,693 ppm and 564 ppm respectively), translating to 288 mg zinc and 96 mg copper per serving. Methionine and lysine are disclosed as percentage minimums. No proprietary blends, no hidden actives.
Source disclosure is clean for a hoof supplement. Most hoof ingredients are synthetic compounds where source doesn’t differentiate quality, but flaxseed is named explicitly as the omega-3 source. The ingredient list is long and detailed, including every inactive from bentonite clay to sorbic acid. Serving instructions specify a 1,100 lb horse reference weight, scoop size, and days per container for all three bucket sizes.
The only point lost: no trademarked ingredient specifications. The zinc methionine complex and copper amino acid complex are described generically rather than by a branded spec like Zinpro or Bioplex. For a mass-market supplement at this price, that’s expected.
14/15 ties Horseshoer’s Secret with BiotinDAILY and Sho-Hoof for the highest Label Transparency score in our Hoof Health database. Seven of the 15 audited products sit 2-5 points lower, usually because of unquantified biotin amounts or ppm values without a stated scoop weight.
Ingredient Form — 17 / 20
Horseshoer’s Secret earns its reputation on mineral form. Zinc methionine complex (form score 4/4) and copper amino acid complex (4/4) are both chelated. Chelated minerals bind to amino acids for transport across the gut wall, and the absorption advantage over oxide or sulfate forms is well-established in equine research, particularly for zinc and copper in hoof tissue.
The remaining ingredients land at standard form quality. DL-methionine (3/4) is the racemic mixture rather than the costlier L-methionine, but it’s the industry baseline and our threshold is calibrated for it. L-lysine (3/4) is the biologically active form. Biotin isn’t specified as D-biotin on the label (3/4). Omega-3 comes from flaxseed, which delivers ALA rather than the more bioavailable DHA/EPA from marine sources (3/4).
Average form score: 3.33 out of 4, multiplied by 5 = 17/20. Two perfect scores and four standard scores.
17/20 places Horseshoer’s Secret in the top tier of our Hoof Health database. Six products score 18 by chelating across a broader mineral panel (HS Extra Strength, Biotin II 22X, Equine Hoof Guard, Formula 707, Biotin Hoof Blast, Hoof & Hair Guard), but none of them combines chelated zinc and copper with a methionine dose above threshold the way this formula does.
Dosing Adequacy — 14 / 20
Hoof Health scores four ingredients: biotin (primary), zinc, copper, and methionine (all secondary). Amounts below are per the recommended 6 oz (170g) daily serving for a 500 kg horse.
Biotin (primary, threshold 20 mg): 15 mg delivered (75% of threshold). Multiple equine studies from the 1990s (notably Josseck 1995 in Lipizzaners) converge on 20 mg/day as the standard for measurable hoof horn improvement. At 15 mg, you’re in the therapeutic range but below the consensus target. Horses with severe hoof problems may not see full benefit. Score: 5 / 8.
Zinc (secondary, threshold 400 mg): 288 mg delivered (72% of threshold). The NRC sets 400 mg/day for maintenance in a 500 kg horse. At 288 mg from a chelated source, effective absorption is better than the raw number suggests, but the gap is real. If your horse’s diet is already low in zinc (common with hay-only diets), this supplement alone won’t close the deficit. Score: 2 / 4.
Copper (secondary, threshold 100 mg): 96 mg delivered (96% of threshold). Nearly there. Copper is essential for keratin cross-linking, and the amino acid complex form absorbs well. The 4 mg shortfall is negligible in practice, especially since most feeds provide some baseline copper. Score: 3 / 4.
DL-Methionine (secondary, threshold 2,500 mg): 2,724 mg delivered (109% of threshold). Methionine is the second-most limiting amino acid in equine diets and a direct sulfur donor for keratin synthesis. Exceeding threshold here is meaningful, and it’s one of the reasons farriers keep recommending this product. Score: 4 / 4.
Total: 5 + 2 + 3 + 4 = 14 / 20. The biotin and zinc shortfalls are the story. Methionine and copper are solid. If Farnam bumped biotin to 20 mg and zinc to 400 mg, this would be an 18+ formula.
14/20 puts Horseshoer’s Secret mid-pack in our Hoof Health database — five products score higher, all by either hitting the 20 mg biotin target (HS Extra Strength at 20/20, Biotin 800 Z at 18/20, Farrier’s Formula DS at 17/20) or loading zinc above 400 mg (Sho-Hoof and Hoof & Hair Guard at 16/20). The methionine surplus offsets the biotin shortfall partially but doesn’t erase it.
Formula Design — 11 / 15
Core completeness: All four core Hoof Health ingredients present: biotin, zinc, copper, methionine. This is the full keratin-synthesis nutrient chain. Score: 6 / 6.
Supporting ingredient breadth: L-lysine (1,704 mg), flaxseed-sourced omega-3s (0.6% min), yeast culture for hindgut support, calcium and phosphorus. Lysine at this level is the most useful of these for hoof work. Score: 3 / 5.
Formula differentiation: Nothing beyond the baseline hoof ingredient set at meaningful doses. No MSM, no silicon, no unusual inclusions that would differentiate the formula beyond the core four. Score: 2 / 4.
Total: 6 + 3 + 2 = 11 / 15. A complete formula without flash.
11/15 is upper-mid for our Hoof Health database. The three products that score 15/15 on Formula Design (HS Extra Strength, Biotin II 22X, Farrier’s Formula DS) all add either MSM, silicon, or a broader B-vitamin panel on top of the core four. Horseshoer’s Secret stays conservative, which is part of why the price stays conservative.
Quality Assurance — 7 / 15
Farnam is a founding member of the National Animal Supplement Council and has held the NASC Quality Seal since 2002. NASC membership requires independent audits of manufacturing facilities, adverse event reporting, random product testing for label accuracy, and compliance with FDA cGMP standards for supplements. This is the strongest publicly-verifiable QA signal available for a hoof supplement in this price range.
What’s missing is the next tier: no published Certificate of Analysis for specific production lots, no NSF or Informed Sport certification for competition safety, and no third-party contamination testing results visible on the product page. For a supplement that a reining or Western pleasure horse owner might feed alongside show-ring work, the absence of sport certification is a real gap.
Important context: This score reflects publicly available documentation, not a judgment of actual product quality. Farnam is a subsidiary of Central Garden & Pet (a publicly traded company) with decades of manufacturing history and an Amazon’s Choice badge in the hoof supplement category. The company can improve this score by publishing COAs, obtaining NSF or Informed Sport certification, or describing their QC program publicly in more detail. We welcome Farnam to contact us at contact@equineauditlab.com with updated documentation.
7/15 is the highest Quality Assurance score in our Hoof Health database, tied with Horseshoer’s Secret Extra Strength. Both products earn the score through NASC Quality Seal membership — nine of the 15 audited Hoof Health products score 0 or 1 on this dimension because they publish no third-party QA signal at all.
Value — 9 / 15
Horseshoer’s Secret has a loading-then-maintenance dosing schedule: 6 oz/day for the first 6-8 months, then 3 oz/day for ongoing maintenance. All cost calculations use the recommended 6 oz dose, which is what you’ll feed for the first half-year or more. At maintenance (3 oz), per-day costs drop to roughly half.
Cost Per Effective Day (CPED): $144.59 (38 lb bucket, Amazon, April 2026) ÷ 101 days = $1.43 per day. Score: 7 / 8.
Cost Per Gram of Primary Active (CPG): $1.43 ÷ 0.015 g biotin = $95.33 per gram. Biotin is dosed in milligrams, so cost-per-gram values are inherently very high for all hoof supplements. This sub-score sits near zero for every product in the Hoof Health category by design. Score: 0 / 5.
Size options: Three sizes — 11 lb ($47.99, 30 days), 22 lb ($86.67, 60 days), 38 lb ($144.59, 101 days). Moving from the 11 lb to the 38 lb saves roughly $0.17/day. Score: 2 / 2.
Total: 7 + 0 + 2 = 9 / 15.
Context on Value: The CPG sub-score is structurally capped near zero for hoof supplements because biotin is an expensive micro-nutrient per gram. This is by design in our scoring system, which means hoof products compete primarily on CPED, a fairer comparison for this category.
9/15 places Horseshoer’s Secret mid-pack for Hoof Health Value. Eight biotin-lighter products score 10/15 by sitting below $0.75/day in absolute cost, but they reach that score while scoring lower on Formula Design and Dosing Adequacy. Among the four Recommended-badge products in our database, only Biotin 800 Z beats Horseshoer’s Secret on Value — and Biotin 800 Z carries no methionine.
The Bottom Line
Horseshoer’s Secret is the cheapest Hoof Health product in our database to earn a Recommended badge, and the only one that exceeds the methionine threshold. At 2,724 mg of DL-methionine per 6 oz serving (109% of the 2,500 mg target), it delivers the single highest methionine dose we’ve audited, backed by chelated zinc and copper complexes and an NASC Quality Seal since 2002. The 15 mg biotin is the trade-off — 25% below the 20 mg consensus target that Horseshoer’s Secret Extra Strength and Farrier’s Formula DS both hit, and owners of horses with active hoof cracks will notice. Buy it if your horse is on maintenance hoof care or mild-improvement mode and you want a full four-nutrient formula under $1.50/day. Skip it if your horse has visible structural damage (thin soles, chronic quarter cracks, collapsed heels) and go straight to HS Extra Strength or Farrier’s Formula DS, where the 20 mg biotin dose justifies the higher price. Amazon’s 845 customer ratings currently average 4.8 stars, and the product holds Amazon’s Choice status in the hoof supplement category.
Overall: 7.2/10.
Product Specifications
| Specification | Detail |
|---|---|
| Form | Pellets (alfalfa-based) |
| Serving size | 6 oz / 170g (recommended loading) / 3 oz (maintenance after 6-8 months) |
| Container sizes | 11 lb, 22 lb, 38 lb |
| Servings per container (38 lb) | 101 days at recommended dose |
| Price (38 lb) | $144.59 (Amazon, accessed April 2026) |
| Cost per day | ~$1.43 (recommended dose) / ~$0.71 (maintenance) |
| Country of origin | USA |
| Sport safety | NASC Quality Seal. No NSF or Informed Sport certification. |
Active ingredients per 6 oz (170g) recommended serving:
| Ingredient | Amount | Threshold (500 kg horse) | % of Threshold |
|---|---|---|---|
| Biotin | 15 mg | 20 mg | 75% |
| DL-Methionine | 2,724 mg | 2,500 mg | 109% |
| L-Lysine | 1,704 mg | — | — |
| Zinc (zinc methionine complex) | 288 mg | 400 mg | 72% |
| Copper (copper amino acid complex) | 96 mg | 100 mg | 96% |
| Omega-3 fatty acids (from ground flaxseed) | 0.6% min | — | — |
| Omega-6 fatty acids | 0.15% min | — | — |
| Yeast culture (dehydrated) | Present (not quantified) | — | — |
| Calcium | ~3,740 mg (2.2% min) | — | — |
| Phosphorus | ~850 mg (0.5% min) | — | — |
Frequently Asked Questions
Is 15 mg of biotin enough for my horse?
For general maintenance and mild hoof improvement, 15 mg sits in the therapeutic range and many horses respond well to it. For horses with chronic cracking, thin soles, or serious structural issues, the research points to 20 mg as the target. If you need the extra 5 mg, you can add a standalone biotin supplement alongside Horseshoer’s Secret. Standalone biotin runs roughly $0.15-0.25/day and won’t disrupt the existing mineral balance.
Is Horseshoer’s Secret or Farrier’s Formula DS better for my situation?
Both earned Recommended badges and cost almost the same ($1.43 vs $1.40/day). The split is between biotin dose and published QA. Farrier’s Formula DS hits 20 mg biotin and scores 17/20 on Dosing, but its QA is 2/15 and part of its mineral panel uses zinc oxide. Horseshoer’s Secret delivers 15 mg biotin (14/20 Dosing) with fully chelated zinc and copper, and scores 7/15 on QA thanks to NASC membership since 2002. In most real-world use, we’d nudge toward Horseshoer’s Secret — the 5 mg biotin gap is cheap to close with a standalone top-up, but you can’t retroactively add QA documentation. Our full Horseshoer’s Secret vs Farrier’s Formula DS comparison walks through both profiles in more detail.
Why does the product have a loading and maintenance dose, and does that matter?
Hoof growth is slow; a full hoof capsule takes 8-12 months to grow out. The 6 oz loading dose delivers higher nutrient levels during the active improvement phase, then the 3 oz maintenance dose keeps levels adequate once hoof quality has improved. At maintenance, all nutrient amounts drop by half, so biotin goes from 15 mg to 7.5 mg. That’s below the therapeutic range, which matters if your horse still has ongoing hoof issues. In that case, stay on the 6 oz loading dose rather than drop to maintenance.
Sources
- Farnam — Horseshoer’s Secret Pelleted Hoof Supplement product page (accessed April 2026). Feeding directions for loading (6 oz/day) and maintenance (3 oz/day) phases; container sizes (11 lb, 22 lb, 38 lb) and verified product names.
- Mad Barn Feed Bank — Horseshoer’s Secret nutritional analysis (accessed April 2026). Complete nutritional profile: scoop size (170g), per-serving mineral amounts, full ingredient order.
- Amazon — Horseshoer’s Secret 38 lb bucket (ASIN B001DEIKZO) (accessed April 2026). Price source: $144.59 (list $151.99). Customer rating: 4.8 stars across 845 ratings. Amazon’s Choice badge in hoof supplement category.
- Horse.com — Horseshoer’s Secret product listing (accessed April 2026). Guaranteed Analysis values used for scoring: Copper 564 ppm, Zinc 1,693 ppm, Biotin minimum 40 mg/lb.
- Valley Vet Supply — Horseshoer’s Secret (accessed April 2026). Per-serving ingredient table used for Dosing Adequacy calculation: 15 mg biotin, 1,704 mg lysine, 2,724 mg DL-methionine per 6 oz serving.
- Farnam — NASC: What It Means to You and Your Horse (accessed April 2026). NASC founding membership date (2002), Quality Seal compliance requirements, cGMP manufacturing standards.
- NASC — Quality Seal program (accessed April 2026). Independent facility audit requirements, random product testing protocol, adverse event reporting standards, used for QA dimension scoring.
- National Research Council. Nutrient Requirements of Horses, 6th Revised Edition. National Academies Press; 2007. Chapter 5 (Minerals), Table 5-1: zinc (400 mg/day) and copper (100 mg/day) maintenance requirements for a 500 kg adult horse. Used as Dosing Adequacy thresholds.
- Josseck H, Zenker W, Geyer H. “Hoof horn abnormalities in Lipizzaner horses and the effect of dietary biotin on macroscopic aspects of hoof horn quality.” Equine Veterinary Journal 1995;27(3):175-182. Multi-year study establishing 20 mg/day biotin as the dose required for measurable hoof horn improvement in adult horses. Used as Dosing Adequacy threshold for biotin.