How Do You Read A Certificate Of Analysis For Enclomiphene Citrate?

Disclaimer. Enclomiphene citrate is supplied strictly as a laboratory research chemical. It is not for human consumption, not for veterinary use, and not for any diagnostic or therapeutic application. This article covers analytical documentation and is written for educational and research purposes. Nothing here describes how to handle, prepare, or administer the material. Qualified researchers are responsible for their own handling procedures under applicable law.

Read the certificate in a fixed order: batch linkage first, identity second, method third, result last. Most readers go straight to the purity percentage. For this particular chemical, that figure is the least informative number on the page.

The reason is structural. Enclomiphene citrate has no United States Pharmacopeia monograph. FDA stated this plainly in its 2022 review of the material for the 503A Bulks List, and also noted that the material is not recognized in the European or Japanese pharmacopeias. No compendial monograph means no standard method and no standard acceptance criteria. Every certificate in this market runs an in-house method against in-house limits. So the method column carries more information than the result column.

We stock research chemicals at Nordic Chems, and this is the order we read a certificate in before anything reaches the catalog. Here are the 8 checks.

What Is a Certificate of Analysis for Enclomiphene Citrate?

A certificate of analysis for enclomiphene citrate is a lab-issued document reporting the test results for one specific production batch. It records what the material was confirmed to be, how pure it measured, which analytical methods produced each result, the batch or lot number, and the date of testing. It is batch-specific evidence, not a general product claim.

Check 1: Does the Batch Number Tie to Your Container?

A certificate that cannot be traced to the container in your hand proves nothing about your material. Look for a batch or lot number printed on the document that matches the label on your container, plus a test date.

This is where most transparency claims fall apart. A supplier can publish an impressive certificate and ship from a different batch. The fix is simple and you should expect it from anyone selling to researchers: ask which batch your order shipped from, and expect a specific answer rather than a link to a general document. Where a supplier publishes test results, as we do on our quality control page, the published document still has to carry a lot number before it tells you anything about what you received.

Check 2: Match the CAS Number to the Salt Form

This is a 10-second check that catches real errors. Enclomiphene citrate and enclomiphene free base are different materials with different CAS numbers and different masses.

Enclomiphene citrate is CAS 7599-79-3, molecular formula C32H36ClNO8, molecular weight 598.08 g/mol. The free base, also called trans-clomiphene, is CAS 15690-57-0, molecular formula C26H28ClNO, molecular weight 405.96 g/mol. Both figures are confirmed against the PubChem entry maintained by the National Center for Biotechnology Information.

The gap matters. One gram of the citrate salt carries roughly 679 mg of free base, a difference of about 32 percent by mass. A certificate headed "Enclomiphene Citrate" that carries CAS 15690-57-0 is naming the free base. Either the heading is wrong or the identity line is wrong, and you cannot tell which without asking. I have found this exact mismatch on live vendor pages in this market more than once.

Check 3: Confirm Identity With the Right Instrument

Purity and identity answer different questions. Purity asks how much of the sample is one substance. Identity asks which substance that is. A sample can be 99 percent pure and 99 percent pure something else.

Identity work usually appears as FTIR, mass spectrometry, or NMR. Mass spectrometry gives you molecular mass confirmation, which FTIR does not. A certificate that reports identity as "conforms" with no instrument named has reported an opinion rather than a measurement.

Check 4: Why Does the Isomer Line Matter More Than the Purity Number?

Because enclomiphene is one half of a pair, and the other half looks almost identical to an analytical method that is not set up to separate them.

Clomiphene citrate is a mixture of 2 geometric isomers: the trans isomer, which is enclomiphene, and the cis isomer, which is zuclomiphene. Enclomiphene is produced by separating them. FDA's review puts a number on the starting ratio. Based on the USP clomiphene monograph, enclomiphene content in clomiphene citrate is about 50 to 70 percent.

Sit with that figure. If a separation runs poorly and the release method does not resolve the 2 isomers, a sample can report high total purity while carrying a meaningful fraction of the wrong isomer. The purity number is not lying. It is answering a question you did not ask.

So look for a dedicated line. It may be labelled Z-isomer, cis-isomer, isomeric purity, or trans content. The result should carry its own method, typically HPLC with a column that resolves the pair, sometimes supported by NMR. A certificate with a 99 percent purity figure and no isomer line has left the single most relevant question about this chemical unanswered. That is the check that separates a useful document from a decorative one. When our enclomiphene listings go live, the isomer line is the first thing we will read on the incoming certificate.

Check 5: Make the Purity Figure Name Its Method

Since no monograph governs this material, "99 percent purity" is a claim about an unnamed procedure until the certificate names the procedure.

Look for the technique, the detection mode, and the acceptance criterion side by side. HPLC with UV detection at a stated wavelength and a stated specification is a real result. A bare percentage with the word "conforms" next to it is a result you cannot evaluate. Watch for the phrase "predictive model" in the method column as well, which marks a value that was calculated rather than measured.

Check 6: Look for Named Impurities, Not a Lump Total

FDA's review tells you what to look for. It states that the impurity profile is expected to resemble clomiphene citrate as outlined in the USP monograph, and that likely impurities include residual cis-clomiphene citrate and binaphthyl-phosphoric acid used in the manufacturing process.

That gives you a 2-item checklist from a government source. Residual cis-clomiphene is the isomer question again, arriving from the separation step. Binaphthyl-phosphoric acid is a process residue from the resolution chemistry. A certificate that reports total impurities as a single lump figure, with no named impurities and no residual solvent data, is telling you less than FDA already told you for free.

Check 7: Elemental Impurity and Water Methods Go Stale

This one catches old templates. USP omitted General Chapter 231, Heavy Metals, from USP-NF with an official implementation date of January 1, 2018, and replaced it with General Chapter 232, Elemental Impurities Limits, and General Chapter 233, Elemental Impurities Procedures. FDA published guidance material covering the same transition.

The change was not cosmetic. The old chapter 231 was a century-old qualitative colorimetric test. The replacement chapters cover 24 elements sorted into 3 classes by toxicity and call for quantitative measurement by ICP-OES or ICP-MS, down to parts per billion. A certificate dated 2026 that still cites USP 231 for heavy metals is running a method the compendium dropped more than 8 years ago, and reporting a pass or fail where a number should be.

Water content should carry a method too, typically Karl Fischer titration under USP chapter 921, with an actual percentage rather than a conformance mark.

Check 8: Who Signed It, and What Is That Lab Accredited to Do?

Name the lab or the certificate is anonymous. A document with no issuing laboratory, no signature, and no contact details is a marketing asset rather than a test record.

Accreditation claims deserve scrutiny, including ours and everyone else's. ISO/IEC 17025 covers the competence of testing laboratories, and accreditation is granted by an accreditation body against a defined scope. A lab accredited for one technique is not accredited for every technique it offers. If a certificate carries an accreditation logo, the questions are which body granted it, what the certificate number is, and whether the method used on your batch falls inside the listed scope. A logo with no scope document behind it is decoration.

Watch for a related blur. ISO 9001 is a quality management standard describing how an organization runs its processes. It is not laboratory accreditation and does not substitute for it. Suppliers sometimes present one as evidence of the other. They are different claims about different things.

What Storage Information Belongs on the Document?

FDA's review notes that enclomiphene citrate is slightly soluble in water, which makes particle size and polymorphism relevant to solid forms, and that the material is expected to be stable under the storage conditions that apply to clomiphene citrate: controlled room temperature, protected from light.

Protection from light is the detail that gets dropped. A certificate should state temperature range, light protection, and container condition. The condition of the seal when a package arrives is itself a data point about whether storage held in transit.

A COA Review Checklist for 2026

Run the document against these 10 points. The first phrasing in each is what a strong certificate shows. The second is the version that should slow you down.

1. Batch linkage. A lot number plus a test date you can trace to your container, rather than a generic specification sheet with no lot number on it.

2. Material and CAS. The salt form named and CAS 7599-79-3 given for the citrate, rather than the free base CAS sitting under a citrate heading.

3. Identity. FTIR, mass spectrometry, or NMR named as the method, rather than the word "conforms" standing alone.

4. Isomeric purity. A dedicated Z-isomer or isomeric purity line carrying its own method, rather than no isomer line at all.

5. Purity. Technique, detection mode, specification, and measured value together, rather than a percentage on its own.

6. Impurities. Named impurities including residual cis-clomiphene, rather than a single total or nothing.

7. Elemental impurities. ICP-MS or ICP-OES under USP chapters 232 and 233 with real numbers, rather than USP 231 or a bare pass or fail.

8. Water content. Karl Fischer with a measured percentage, rather than an omission.

9. Laboratory. A named lab with its accreditation body, certificate number, and scope, rather than an unnamed lab or an unsupported logo.

10. Storage. Temperature, light protection, and container condition, rather than generic wording or silence.

What Nordic Chems Currently Supplies

Enclomiphene citrate is planned, not stocked. The collection pages are built and waiting, but publishing testing data for a material we do not yet carry would mean inventing it.

What is in the catalog today is our research chemicals range: Phenibut HCL, Tianeptine Sodium, Tianeptine Sulfate, Agomelatine, Aniracetam, and Pramiracetam, in powders, capsules, and solutions. When enclomiphene arrives it will sit on the 12.5 mg collection and the enclomiphene ordering page, and it will be held to the 8 checks above.

Orders ship within 24 hours excluding weekends and holidays. United States delivery usually runs 2 to 5 business days. We ship to the United States and Canada.

Research Use Only

Enclomiphene citrate and every material referenced in this article are sold and discussed strictly for laboratory research and educational purposes. They are not for human consumption, not for veterinary use, and not intended to diagnose, treat, cure, or prevent any condition. Enclomiphene citrate is not an FDA-approved product.

Buyers must be at least 18 years of age and must confirm they understand these are regulated chemicals for research use only. Accounts we suspect of purchasing outside that purpose are added to a no-sell list and their orders are rejected. Our shipping and ordering terms set out what applies to every order, and you can contact the team with documentation questions. Read a certificate of analysis for enclomiphene citrate the same way you would read one for any other material: methods first, claims last.

FAQs

What is a certificate of analysis for enclomiphene citrate? 

A certificate of analysis for enclomiphene citrate is a lab-issued document reporting test results for one specific production batch. It records the confirmed identity of the material, measured purity, the analytical method behind each result, the batch or lot number, and the test date. It is evidence about one batch, not a general product claim.

What CAS number should appear on an enclomiphene citrate certificate? 

CAS 7599-79-3, with a molecular weight of 598.08 g/mol. The free base, trans-clomiphene, is a different material at CAS 15690-57-0 and 405.96 g/mol. A document headed "Enclomiphene Citrate" carrying the free base CAS has an error in either the heading or the identity line.

Is there a USP monograph for enclomiphene citrate? 

No. FDA stated in its 2022 review for the 503A Bulks List that enclomiphene citrate has no USP compendial monograph, and that it is not recognized in the European or Japanese pharmacopeias either. Every certificate therefore runs an in-house method against in-house acceptance criteria, which is why the method matters as much as the result.

Why does isomeric purity matter on an enclomiphene citrate COA? 

Enclomiphene is the trans isomer of clomiphene, and zuclomiphene is the cis isomer. FDA notes that enclomiphene content in clomiphene citrate runs about 50 to 70 percent based on the USP clomiphene monograph. A total purity figure from a method that does not separate the 2 isomers cannot tell you which one you have, so look for a dedicated Z-isomer or isomeric purity line.

What impurities should an enclomiphene citrate certificate list? 

FDA's review names residual cis-clomiphene citrate and binaphthyl-phosphoric acid, a residue of the manufacturing process, as likely impurities, alongside the profile outlined in the USP clomiphene monograph. A certificate reporting one lump total with no named impurities gives you less than that public source already does.

How do you match a certificate of analysis for enclomiphene citrate to the batch you received? 

Compare the batch or lot number printed on the certificate against the label on your container. If they do not match, or the certificate carries no lot number at all, ask the supplier which batch shipped against your order and expect a specific answer rather than a link to a general document. A published certificate with no lot number on it tells you nothing about the container in front of you.

Does ISO/IEC 17025 accreditation guarantee a reliable result? 

Only within the accredited scope. ISO/IEC 17025 covers laboratory competence and is granted by an accreditation body against a defined list of methods, so a lab accredited for one technique is not accredited for all of them. Check the accrediting body, the certificate number, and whether the method run on your batch falls inside the listed scope.