How MD Products Are Actually Tested: The Quality File

By Dr. Susan Lin, MD | MD HAIR | La Cañada Ventures, Inc.
Published on mdhair.com — The Physician Behind MD HAIR Series

You email a brand and ask what testing they do. Four days later a reply arrives: "All our products undergo rigorous third-party testing in FDA-registered facilities to ensure the highest standards of quality and purity."

Read it again. It names no laboratory. No standard. No report number. No date. No analyte. It does not say what was tested — an ingredient, a batch, the finished product — or what the result was, or what question the test was designed to answer. It is four days of waiting for a sentence that could be printed on anything.

I am Dr. Susan F. Lin, M.D. — Boston University School of Medicine, board-certified in Obstetrics & Gynecology and in Anti-Aging Medicine, and the physician behind the MD® line at La Cañada Ventures, Inc. since 2008. This article is the opposite of that email. It walks the actual quality chain behind our products, layer by layer, naming laboratories, report numbers, standards and dates.

And it does something else, which is the part I think matters more: at each layer it states what that layer does not prove. Then, at the end, it lists what we do not have at all — no randomised placebo-controlled trial on the hair products, and no bioavailability data — because volunteering the gaps is the only thing that makes the rest of it worth reading.

Layer 1 — Raw Material Identity and Standardisation

Everything starts with what arrives on the loading dock, and this is the layer most brands skip entirely when they talk about testing.

Our lilac ingredient is supplied against a written specification: Phytostem VitaFoods Lilac Dry 50N, product code DC2581N, Resources of Nature LLC, revision 07/13/2011. It is a Syringa vulgaris leaf cell culture extract on a maltodextrin carrier, designated for nutritional use. The specification sets:

• Verbascoside content 47.5–52.5% w/w, by HPLC.
• Total microbial count < 1000 cfu/g.
• Arsenic, cadmium, mercury and lead each < 10.0 ppm.

What this proves. That standardised for verbascoside is a measured range on a specification sheet rather than a marketing adjective, and that the incoming material carries defined heavy-metal and microbial limits. When I write that our lilac extract is standardised, that HPLC range is the thing I am referring to.

What it does not prove. A raw-material specification says nothing about the finished capsule, nothing about how much of that material is in it, and nothing about whether any of it does anything. It is an identity-and-purity statement about an input.

Layer 2 — Ingredient Safety

Four studies on the Syringa vulgaris / verbascoside material, each with a named laboratory, a report number and a date. This is, in my honest assessment, the strongest and most under-used part of our file.

What this proves. That the ingredient has been assessed for acute oral toxicity to an OECD guideline, assessed as non-mutagenic in a bacterial reverse mutation assay, found non-irritating on reconstituted human corneal epithelium, and well tolerated in a 20-subject patch test. Those are real findings from named laboratories, and I am glad to have them.

What it does not prove — three things, and I want them stated as plainly as the table.

1. This is ingredient safety, not finished-product safety. These studies were run on the lilac raw material, not on MD Nutri Hair™ and not on any of our topicals. Safety data on one input does not transfer to a finished formulation containing six other things.
2. Safety is not efficacy. Nothing in this table says the ingredient does anything for hair. It says the material did not produce toxicity, mutagenicity or irritation under the tested conditions. Those are different questions and I will not let one stand in for the other.
3. Non-mutagenic in an Ames assay is not clinically proven safe. That phrase does not appear anywhere in our materials and it is not going to. Every one of these findings is bounded by its method, its dose and its duration.

Layer 3 — Manufacturing

MD Nutri Hair™ is manufactured under 21 CFR Part 111, the current Good Manufacturing Practice regulation for dietary supplements, which governs identity testing, purity, contamination control, batch records and label accuracy. Our topicals are cosmetics, manufactured to good manufacturing practice in the same facilities; cosmetic manufacturing obligations are themselves evolving under the Modernization of Cosmetics Regulation Act of 2022, which is still being implemented (FDA, Cosmetics & U.S. Law).

Manufacture is in FDA-registered, GMP-compliant facilities in the United States.

What this proves. That the facility operates to a defined manufacturing standard, is known to the FDA, and may be inspected.

What it does not prove — and this is the single most abused sentence in the supplement industry. FDA-registered describes the facility. It is not FDA approval, review, endorsement or authorisation of the product. No MD product is FDA approved. No cosmetic or dietary supplement on the United States market is FDA approved. If you ever see a brand slide from FDA-registered facility to FDA approved, you have learned how that brand handles every other sentence on its label.

Layer 4 — Finished-Product Microbiological Stability

The finished capsule was placed on an accelerated storage programme with microbiological analysis at 0, 1, 2, 3 and 6 months, conducted per USP General Chapters <2021> and <2022> (USP-NF). MD Nutri Hair™, lot 15294, expiry 10/18. Laboratory controls MB331216 / CH2281116. Health Level One Inc., Hauppauge, New York.

What this proves. That the finished product was held under accelerated conditions and tested at defined intervals for microbiological quality, against pharmacopoeial chapters written for that purpose.

What it does not prove, and this distinction is exact. Microbiological stability is not potency stability. This programme tested for microbial contamination over time. It did not assay verbascoside, biotin, niacinamide or vitamin E content across shelf life, so it does not substantiate active retention to the expiry date. Anyone — including us — who describes this simply as stability tested without the word microbiological has overstated it by a full category. Polyphenols in particular oxidise with light, air and time, which is precisely why the distinction matters rather than being a pedantic one.

I would like to have potency-stability data. We do not currently hold it in the readable file.

Layer 5 — Independent Analytical Testing

A separate package of work was carried out by an independent Canadian analytical laboratory in November–December 2014, running to more than a hundred pages. Two things in it are worth your attention.

Pesticide residue screening, by GC-MS. The panel includes trans-γ-chlordane, endosulfan II, prothiofos, profenofos, fenthion-sulfone, ethion and pyrethrins, run against a carbophenothion internal standard and calibrated across 10–2000 ppb. Final concentrations read 0 on the analytes sampled.

Vitamin label-claim conformance, by LC-MS/MS — fat-soluble (A palmitate, D-2, D-3, E acetate) and water-soluble (B1, B2, B3, B5, B6, B12, biotin, folic acid, choline) — with results checked against specification limits. As a worked example: vitamin E acetate measured at 4 mg per capsule against a 2–6 mg per capsule specification limit.

The work carries method validation with system suitability met: acceptance criteria of RSD not more than 5.0% and R² not less than 0.99, with observed values including biotin RSD 3.8% / R² 1.00, vitamin D-3 3.3%, vitamin E acetate 3.0% and vitamin D-2 4.8%. Instrumentation: Waters Acquity UPLC C18 and Restek Ultra IBD columns, LC-MS/MS.

What this proves. That an independent laboratory screened for pesticide residues and confirmed vitamin content against label specification, on validated methods that met their own system-suitability criteria. Label-claim conformance is a genuinely meaningful check: the recurring scandal in this industry is products that do not contain what the panel says they contain.

What it does not prove — three caveats, all of which I would rather say than have found.

1. This is not stability testing, and we do not describe it as such. It is a point-in-time analysis of pesticide residues and vitamin content.
2. Label-claim conformance is not a clinical outcome. Confirming that a capsule contains the vitamin E it says it contains tells you the label is accurate. It tells you nothing about whether anyone's hair changed.
3. The package spans multiple dosage forms — capsules, tablets and gummies — so it covers more than one product. Any specific figure must be attached to the specific analytical report number and product it belongs to, and not floated free as a general quality claim. That discipline is the reason I am flagging it here rather than quoting a headline number at you.

Layer 6 — Human Evidence, at Its Real Weight

This is where most brands' quality pages become marketing. Here is ours, stated as I would state a competitor's.

The 30-day in-office consumer use study — MD Nutri Hair™ only. In a 30-day in-office consumer use study (30 subjects, self-reported), 95% saw improved hair appearance, 90% reported better manageability, and 75% reported increased fullness. Individual results vary; study on file.

It is a perception study. No hair was counted, no follicle measured. It was not randomised and had no control arm, so I cannot tell you what a control group would have reported — and self-reported outcomes are precisely the class where expectation exerts the most influence. These three figures belong to MD Nutri Hair™ and to nothing else; applying a supplement's figure to a shampoo or a conditioner would be a misattribution, and we do not do it.

The 119-day (17-week) Spincontrol North America study — the topical system. Conducted by an independent third-party testing organisation on the two-step topical system rather than either product used alone: 24 subjects — 12 men and 12 women, aged 20 to 44, with chronic or acute hair loss — applying the system once daily for 119 days (17 weeks). On the study's self-evaluation questionnaire, 71% agreed their hair growth had improved — a result the report records as statistically significant on a chi-squared test of favourable versus unfavourable opinions. A second significant finding from the same questionnaire: 75% said they would recommend the two-step system to their friends.

Four things travel with those figures every single time. They were self-reported — a questionnaire, not a hair count. There was no placebo arm. Seventeen weeks is long enough for hair-cycle changes to begin appearing, which is more than most claims in this category can say. And the application was a hemi-head design — the two-step system on one side of the head — which limits some person-to-person variability but is not a placebo comparison, and I will not describe it as one.

And then the report's own sentence, from the same document: "The satisfaction rate (concerning the overall efficacy) is not significantly validated."

That line is in the study we paid for. Quoting the percentages without it would be selective quotation from a discoverable document, and I would rather you read it here than find it later.

What We Do Not Have

The layers above are real. This section is what makes them credible.

No randomised, placebo-controlled trial on the hair products. Not one. Randomisation is what makes causal inference possible (Schulz et al., 2010); blinding is what protects an outcome from expectation (Hróbjartsson & Gøtzsche, 2010). We have neither. That places our evidence in the middle of the ladder, not the top, and no amount of laboratory documentation moves it up.

No bioavailability or absorption data. I have not located bioavailability data for the oral ingredients in the readable file. So I cannot tell you what fraction of orally administered verbascoside reaches circulation, let alone the follicle, and I do not make absorption claims. If such data exists, it will be read before any claim is built on it — not after.

No potency stability over shelf life. See Layer 4. Microbiological, yes. Assay, no.

No peer-reviewed publication of our own product studies. The Wisuitiprot work on verbascoside is peer-reviewed and open access (PMID 35087085); our studies are not published, and independent peer review is a different order of scrutiny from a report on file.

No pregnancy or lactation safety data. These studies are not conducted on cosmetics and supplements. The MD Nutri Hair™ label states it directly: do not take if you are pregnant or breast feeding. The label controls, and it is stricter than ask your doctor.

Individual amounts inside the proprietary blend are undisclosed. MD Nutri Hair™ declares a Proprietary Blend of 300 mg; the split between flaxseed powder, lignan powder and lilac is not published. Lawful, and still our weakest transparency answer.

Ingredient safety data does not cover every ingredient. The Layer 2 dossier is on the lilac material. It is not a safety file on the whole formulation.

And one document we hold and refuse to cite. Our archive contains a preliminary, unpublished supplier report on the raw material. It is not peer-reviewed and it has never been published, so it does not meet the standard we set for anything that appears in our copy, and we do not cite it. Our archive also contains a file whose name suggests FDA support for lilac. It is nothing of the kind: it is a 1998 notification letter that an unrelated company filed with the FDA about a different product, in a different category, making a claim about a different organ entirely. We read it, established what it was, and set it aside. A notification is a filing, not an approval — and someone else's filing is not even ours.

The Bottom Line

A real quality file has names, numbers and dates in it. Ours does: specification DC2581N with verbascoside at 47.5–52.5% w/w by HPLC; OECD 420 acute oral toxicity and OECD 471 bacterial reverse mutation at Biolab Spa (SAM2075, SAM4014); non-irritating on reconstituted human corneal epithelium; a 20-subject patch test at Kalibios with an irritation index below 0.5; manufacture under 21 CFR Part 111 in FDA-registered, GMP-compliant facilities; finished-product microbiological stability at 0/1/2/3/6 months per USP <2021>/<2022> at Health Level One; pesticide screening and vitamin label-claim conformance at an independent Canadian laboratory on validated methods.

And each layer answers a narrow question. Ingredient safety is not finished-product efficacy. Microbiological stability is not potency stability. Label-claim conformance is not a clinical outcome. Facility registration is not product approval.

What we do not have is a randomised placebo-controlled trial, bioavailability data, potency-stability data, peer-reviewed publication of our own studies, and disclosure of the amounts inside a 300 mg proprietary blend.

When you ask any brand what testing they do, ask for the shape of this article back: the laboratory, the standard, the report number, the date, and what the test does not establish. The last item is the one that separates a quality file from a paragraph of adjectives.

Dr. Susan Lin's Clinical Perspective

"In medicine you learn to read a result by first asking what question the test was built to answer. A negative culture does not mean the patient is well; it means no organism grew under those conditions. The same discipline belongs on a quality file, and it is almost never applied there. A brand will hold an ingredient toxicology study and let a customer read it as proof the finished product works. Nobody lied — the study is real, the report number is real — but the reader crossed four categories in one sentence and the brand let them. So I have made a rule for our own materials: every finding is published with its boundary attached, in the same paragraph, at the same size. It makes our copy longer and less exciting. It also means that when I do tell you something, you can work out exactly how much weight it will bear, which is the only kind of trust worth having in this industry."

— Dr. Susan F. Lin, M.D., Physician Formulator, MD HAIR

Mechanism Spotlight: Why Each Test Answers Only Its Own Question

It is worth understanding why these layers do not substitute for one another, because the reason is structural rather than legalistic.

An Ames test exposes bacterial strains carrying specific mutations to a compound, with and without a mammalian metabolic activation system, and asks whether reversion to growth increases. It is a screen for a compound's potential to damage DNA. Its output is a yes/no on genotoxic potential — it has no channel through which it could say anything about hair, because nothing in the experiment involves a follicle.

An acute oral toxicity study to OECD 420 administers a fixed dose and observes for 14 days, classifying under the Globally Harmonised System. It answers: does a single large dose cause acute harm. Chronic exposure, subtle metabolic effects and efficacy are all outside its design.

A reconstituted human corneal epithelium assay applies a test material to a three-dimensional tissue model and measures cell viability by MTT reduction. It answers: is this material irritating to that tissue. It is a replacement for an animal irritation test, not a bioactivity screen.

A USP <2021>/<2022> microbiological programme enumerates microorganisms and screens for specified organisms at intervals. It answers: is the product microbiologically acceptable over storage. It never quantifies an active, because those are different analytical methods — enumeration versus chromatographic assay — and the samples are prepared differently.

An LC-MS/MS label-claim assay quantifies specific analytes against calibrated standards. It answers: is the declared amount actually present. It cannot tell you whether that amount is absorbed, or sufficient, or clinically relevant.

A randomised controlled trial is the only design on the list that can answer did this product cause a change, and it can do so precisely because randomisation distributes known and unknown confounders across arms by chance rather than by assumption, and blinding protects the outcome from expectation.

Stack them and you have a quality chain — identity, purity, safety, manufacturing control, microbiological integrity, label accuracy. Stacked high enough, it still does not add up to an efficacy finding, because none of its rungs is pointed at that question. That is not a criticism of the chain. It is what the chain is for, and knowing the difference is what lets you read any brand's testing page in about ninety seconds.

Recommended Reading

Pillar pages on mdhair.com:

• The Clinical Evidence Behind MD HAIR
• The Lilac & Verbascoside Science
• Drug-Free Hair Loss Treatment — The Complete Guide
• About Dr. Susan Lin, M.D. — The Physician Behind MD®

Related articles in this series:

• What "Physician-Formulated" Should Mean — And How to Check — the accountability half of this article's quality standard
• Plant Stem Cell Culture and Why Standardization Beats Potency — Layer 1 of this file, in full: named molecule, named method, defined range
• Cosmetic, Supplement, or Drug? — the regulatory categories that decide what any of this testing is allowed to claim
• How Long Until You See Results? A Realistic Month-by-Month Hair Growth Timeline — why a 17-week study duration is a strength worth naming, and why shorter ones are not

Our sister site md-factor.com publishes the corresponding quality documentation for the wider MD® portfolio under the same standard.

MD HAIR Product Recommendation

None. A transparency article that ends in a sale is an advertisement wearing a lab coat.

Two links instead:

The Clinical Evidence Behind MD HAIR — the human evidence in Layer 6, set out with the same boundaries attached: the consumer use study figures with their perception-study caveat, and the 119-day Spincontrol study with its 24 subjects, its hemi-head design, its self-reported outcomes, its absent placebo arm, and the report's own line about validation. If you would like the studies on file, ask us.

The MD HAIR Quiz — because no quality file answers the question that actually matters to you, which is what is driving your hair change. Several of its outcomes route you to a physician and a laboratory panel — full thyroid panel, serum ferritin, vitamin D, and where indicated androgen studies — rather than to any product of ours. A certificate of analysis cannot diagnose you.

A note on authenticity: genuine MD HAIR™ and MD Nutri Hair™ products are sold only through mdhair.com, md-factor.com, and the official La Cañada Ventures, Inc. stores on Amazon and Walmart. Every lot number, specification and report in this article belongs to material we sourced and product we manufactured. For a unit bought elsewhere, we cannot verify the lot, the storage, the handling or the label — which means none of this file applies to it.

References

1. OECD. Test No. 420: Acute Oral Toxicity — Fixed Dose Procedure, OECD Guidelines for the Testing of Chemicals, Section 4. oecd.org
2. OECD. Test No. 471: Bacterial Reverse Mutation Test, OECD Guidelines for the Testing of Chemicals, Section 4. oecd.org
3. OECD. Test No. 492: Reconstructed Human Cornea-like Epithelium (RhCE) Test Method — cited as method context only; MD's 2007 ocular study predates this guideline and was an MTT assay on SkinEthic reconstituted human corneal epithelium. oecd.org
4. United Nations. Globally Harmonized System of Classification and Labelling of Chemicals (GHS). unece.org
5. United States Pharmacopeia. General Chapter <2021> Microbial Enumeration Tests — Nutritional and Dietary Supplements (USP-NF) and General Chapter <2022> Microbiological Procedures for Absence of Specified Microorganisms — Nutritional and Dietary Supplements.
6. 21 CFR Part 111 — Current Good Manufacturing Practice for Dietary Supplements. eCFR
7. 21 CFR § 101.36 — Nutrition labeling of dietary supplements (Supplement Facts panel and proprietary blend declaration). eCFR
8. U.S. Food and Drug Administration. FDA Authority Over Cosmetics: How Cosmetics Are Not FDA-Approved, but Are FDA-Regulated. fda.gov
9. U.S. Food and Drug Administration. Cosmetics & U.S. Law — including the Modernization of Cosmetics Regulation Act of 2022 (MoCRA). fda.gov
10. Dietary Supplement Health and Education Act of 1994, Public Law 103-417 (full text, NIH Office of Dietary Supplements). ods.od.nih.gov
11. U.S. Federal Trade Commission. (2022). Health Products Compliance Guidance. ftc.gov
12. Schulz KF, Altman DG, Moher D, for the CONSORT Group. (2010). CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials. BMJ, 340, c332. PMID 20334633
13. Hróbjartsson A, Gøtzsche PC. (2010). Placebo interventions for all clinical conditions. Cochrane Database of Systematic Reviews, Issue 1, CD003974. PMID 20091554
14. Dhurat R, Saraogi P. (2009). Hair evaluation methods: merits and demerits. International Journal of Trichology, 1(2), 108–119. PMID 20927232
15. Wisuitiprot V, Ingkaninan K, Waranuch N, et al. (2022). Effects of Acanthus ebracteatus Vahl. extract and verbascoside on human dermal papilla and murine macrophage. Scientific Reports, 12, 1491. PMID 35087085 · open access
16. U.S. Food and Drug Administration. Biotin Interference with Troponin Lab Tests — Assays Subject to Biotin Interference. fda.gov
17. Internal documentation referenced in this article and available on request: raw material specification DC2581N (Resources of Nature LLC, rev. 07/13/2011); Biolab Spa reports SAM2075 (15/06/2004) and SAM4014 (30/05/2007 and May 2007); Kalibios report 07-77/04-05 (October 2007); Health Level One Inc. accelerated microbiological stability set, MD Nutri Hair™ lot 15294, controls MB331216 / CH2281116; independent Canadian analytical laboratory package, November–December 2014; 30-day in-office consumer use study, MD Nutri Hair™ (30 subjects); Spincontrol North America 119-day (17-week) study, ref. XX-MI01-QV-SE10, 24 subjects. Studies on file.

Dr. Susan F. Lin, M.D. is the physician formulator behind MD HAIR and MD Nutri Hair™, product lines of La Cañada Ventures, Inc. — physician-formulated since 2008 under the MD® mark (U.S. Reg. No. 4,471,494). She trained at Boston University School of Medicine and is board-certified in Obstetrics & Gynecology and earned board certification in Anti-Aging Medicine (A4M).

MD® products are cosmetics and dietary supplements manufactured in FDA-registered, GMP-compliant facilities. "FDA-registered" describes the facility, never the product: these products are not FDA approved, and no cosmetic or dietary supplement is. Individual results vary. MD Nutri Hair™ is a dietary supplement. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

MD Nutri Hair™ is for adults only, one capsule daily. Per the product label: do not take if you are pregnant or breast feeding. Because there are no clinical data in pregnant or breastfeeding women, we do not advocate using MD HAIR products during pregnancy or lactation.

Laboratory findings described in this article relate to ingredient safety, purity, manufacturing control and label conformance. They are not efficacy findings and are not presented as such. This article is for educational purposes and does not constitute medical advice. Consult your own physician for personalized guidance.

Explore more in The Physician Behind MD HAIR series at mdhair.com/pages/dr-susan-lin