Tianeptine Sodium vs. Tianeptine Sulfate: Which Form Suits Your Research?

Written By: Neat Digital, Research Content Writer

Reviewed By: Natalie Kunsman, M.D., Board-Certified Physician

Last Reviewed: August 29, 2026

Tianeptine sodium and tianeptine sulfate are two salts of the same molecule, and that one fact settles most of the confusion in any tianeptine sodium vs sulfate comparison. Dissolve either one and you get the same tianeptine ion in solution. What changes is the salt wrapped around it. The sodium form is the sodium salt of tianeptine's carboxylic acid, water-soluble and quick to pull in moisture. The sulfate form is a hemisulfate, built on the molecule's basic nitrogen, and it ships as a heavier crystalline material. So the decision rarely rides on potency. What matters is fit: which physical form matches how you dissolve, store, and handle the material on the bench.

One line before the chemistry. Tianeptine sold by Nordic Chems is for laboratory research and educational use only. It is not for human consumption. Everything below describes chemistry, identity, and published research, nothing else.

Tianeptine sodium and tianeptine sulfate are two salt forms of tianeptine, a synthetic molecule studied in neuropharmacology research. The sodium salt (CAS 30123-17-2) forms at the carboxylic acid and dissolves readily in water. The sulfate salt, a hemisulfate (CAS 1224690-84-9), forms at the basic nitrogen and carries a higher molar mass.

Tianeptine Sodium: The Water-Soluble Salt

Tianeptine sodium is the sodium salt of tianeptine, and it's the form most published work refers to. Its formula is C21H24ClN2NaO4S, with a molar mass of 458.9 g/mol and CAS number 30123-17-2, listed on the NIH's PubChem CID 23663953. It presents as a white powder. It dissolves readily in water and takes up moisture from the air, so it's hygroscopic and needs a dry, sealed home.

The structure explains the behavior. The sodium sits on tianeptine's carboxylic acid: the acid gives up its proton, sodium takes that place, and the result is a carboxylate salt that behaves like a water-loving material. Nordic Chems stocks it three ways: a 10 gram powder, a 12.5 mg capsule form, and a 50 mg/ml solution, each tested to 99% purity.

Tianeptine Sulfate: The Hemisulfate Form

Tianeptine sulfate is the hemisulfate salt of the same molecule, and it's a different material from the sodium in more than name. The common commercial form is tianeptine hemisulfate monohydrate, CAS 1224690-84-9, catalogued as PubChem CID 45375836. Hemisulfate means two tianeptine units share one sulfate, a 2:1 ratio, with water of crystallization in the lattice. Reported near 535 g/mol per tianeptine unit, it's heavier than the sodium salt.

Here the acid stays put. The sulfate forms at tianeptine's basic nitrogen instead, so this salt is the mirror image of the sodium's chemistry. Nordic Chems offers it as tianeptine sulfate capsules in 30-count bottles. One caveat worth stating plainly: salt naming in this space is loose, and some suppliers use "sulfate" for a 1:1 form. Match the CAS and molar mass on your certificate of analysis to the exact salt you need before you design around it.

How The Two Salts Differ In Structure

The split comes down to where each salt grabs the molecule. Tianeptine has two handles: a carboxylic acid on its heptanoic-acid tail, with a pKa near 4.22, and a basic nitrogen deeper in the structure. The sodium salt uses the acid handle. The sulfate salt uses the basic one. Same core, opposite ends.

That single fork explains the numbers that follow. The sodium is a lighter 1:1 salt at 458.9 g/mol. The sulfate is a heavier 2:1 hemisulfate near 535 g/mol per unit. And it's the reason their water behavior and moisture uptake don't match, even though the tianeptine inside is identical.

Does The Salt Form Change The Pharmacology? 

No. Once either salt dissolves and dissociates, you're left with the same tianeptine ion in solution, and the counterion, sodium or sulfate, floats off. Whatever the molecule does at its research targets, it does regardless of which salt you started from.

This matters because plenty of product pages imply the sulfate is a distinct active, or hint at a different strength. The chemistry doesn't support that. In the published literature, tianeptine is studied in neuropharmacology work on glutamatergic signaling and synaptic plasticity, and that research describes the molecule, not one salt. That's the opposite of comparing two different molecules, like aniracetam and oxiracetam, where the cores themselves differ. What the salt changes is upstream of the biology: how fast it dissolves, how much water it grabs, how you store it, and how you build a stock solution at a known concentration. Choose the salt for the bench work, not for a potency gap that isn't there.

Why Solubility And Moisture Uptake Separate Them On The Bench

Solubility is the first difference you'll feel when you open the vial. The sodium salt dissolves fast in water and aqueous buffer, which suits a lot of standard preparations. It also draws moisture, so an open container can cake or clump if it sits out. Weigh it quickly, reseal it, and keep desiccant in the jar.

The hemisulfate is a different story, and an honest one: published aqueous-solubility figures are easy to find for the sodium salt and thin for the hemisulfate. Treat the sulfate's dissolution as something to confirm from your certificate or supplier data, not something to assume from the sodium. For organic-solvent stocks, the sodium salt has reported solubility near 20 mg/ml in DMSO and 10 mg/ml in ethanol, useful when an aqueous vehicle won't fit the assay. Either way, a preparation validated for one salt won't transfer cleanly to the other. Solvent choice, working concentration, and vehicle controls all shift with the form you picked.

Tianeptine's Short Half-Life And Why Form Matters In Research

Tianeptine clears fast, and that single property shapes a lot of the research around it. A 2022 paper in Molecules reports tianeptine sodium has a short elimination half-life of about 2.5 hours and a pKa of 4.22. That's why groups have studied sustained-release formats: when a molecule leaves the system quickly, the physical form that controls how it dissolves and releases becomes a live research variable.

For a researcher, the takeaway is about design. If your protocol depends on release rate or dissolution timing, the salt and the format (powder, capsule, or the 50 mg/ml solution) stop being interchangeable details and become part of the method.

Tianeptine Sodium Vs Sulfate: The Side-By-Side

Here's the comparison in one place. Where a value depends on the exact salt you receive, the honest entry is to match it to your certificate of analysis.

Which Tianeptine Form Should Your Research Use?

Match the salt to the method. If your assay runs in water or aqueous buffer and you want the form with the deepest published track record, the sodium salt is the default pick, and it comes as powder, capsule, or a ready 50 mg/ml solution. If your work calls for the hemisulfate specifically, whether to match a referenced protocol or a supplier spec, the sulfate capsules cover that.

Three checks before you order. First, confirm the exact salt and molar mass against the certificate of analysis so your calculations use the right number. Second, decide your vehicle early, because an aqueous plan and an organic-solvent plan lead to different salts and stocks. Third, pick the format that fits your workflow: powder for custom concentrations, capsules for fixed units, solution when you'd rather skip weighing. None of these is a strength decision. They're all handling decisions.

How Is Research-Grade Tianeptine Verified For Identity And Purity?

Identity and purity are only as good as the analytics behind them, and this is where the paperwork earns its place. Every batch of tianeptine from Nordic Chems is guaranteed to 99% purity. Material that falls short is rejected, and a fresh batch is tested before anything reaches stock.

Testing runs through two independent labs: BioRegen Labs in Houston, Texas and Janoshik Analytical in Prague. Methods include HPLC and mass spectrometry, with an LC-MS chromatogram showing retention-time and peak analysis, plus heavy-metal screening on the same sample when a project needs it. Synthesis, quality testing, and distribution run under ISO 9001:2015, certificate number C2024-01140. Each certificate carries a batch or lot number and a test date, and you can tie that certificate to the exact batch you received by emailing your order number. Across 10,600 orders shipped and 20 batches tested to date, the same routine applies, and material leaves induction-sealed and desiccated. The full quality testing approach is published on the site.

Storing And Handling Tianeptine Salts In The Lab

Store both salts cool, dry, and sealed, and treat the sodium as the thirstier of the two. Keep containers tightly closed in a cool, dry place, out of reach of anyone not trained to handle them. The sodium salt's habit of taking up moisture makes desiccant and a fast reseal worth the effort. Prepare stock solutions to your protocol, aqueous for the sodium, and to your validated method for the hemisulfate. Handle with appropriate PPE and standard laboratory safety practices, and follow the regulations that apply to handling, storage, transport, and disposal in your setting.

Is Tianeptine Legal To Buy For Research In 2026?

This one needs a straight answer, because the status is moving. As of August 2026, tianeptine is not approved by the FDA for any medical use, is not generally recognized as safe in food, and does not meet the definition of a lawful dietary ingredient. That is the FDA's stated position. On July 8, 2026, the DEA published a proposed rule to place tianeptine, and specifically its salts, into Schedule I. The public comment window closed on August 7, 2026. The rule isn't final and no effective date is set, but if it is finalized, it would cover both the sodium and the sulfate.

At the state level, the picture is already patchy. The DEA's own proposal notes that at least 15 states have banned or controlled tianeptine, among them Alabama, Florida, Georgia, Michigan, Ohio, and Tennessee. The federal record behind the proposal is blunt about why: poison-center reports tied to tianeptine rose about 1,400% from 2015 to 2023, with most logged exposures causing moderate or major effects. None of that describes a material for human use, and it's the clearest reason this one carries a research-only line.

Nordic Chems ships within the USA and Canada and maintains shipping profiles that keep restricted materials out of the states that regulate them. Every buyer has to read and accept the terms at checkout and declare they're a trained professional who can handle the material properly. Orders are vetted before fulfillment. Because the federal proposal is active and state rules differ, confirming what applies in your jurisdiction and your institution sits with you as the researcher. If you're ordering while the Schedule I proposal is pending, check its status first.

Choosing Between The Two Salts

Strip away the salt names and tianeptine sodium versus tianeptine sulfate stops being a contest. You're choosing packaging for the same molecule. The sodium salt gives you a water-soluble, moisture-hungry material with the longest paper trail. The hemisulfate gives you a heavier 2:1 salt built on the base, better matched to protocols that call for it by name. Neither is stronger. The choice lives in your method: solvent, format, release timing. Get those right and the salt follows.

What outlasts any table is knowing exactly what sits in the vial. A CAS number on a label means little without an HPLC trace, a mass-spec result, a batch number, and a test date you can match to your own order. That's the standard Nordic Chems holds every batch to, at 99% purity, checked by two independent labs. Tianeptine stays a research material here, offered for laboratory work and never for human consumption.

FAQs

What's the difference between tianeptine sodium and tianeptine sulfate? 

They're two salt forms of the same molecule. Tianeptine sodium (CAS 30123-17-2) is a 1:1 sodium salt built on the carboxylic acid, near 458.9 g/mol, and readily water-soluble. Tianeptine sulfate is a hemisulfate (CAS 1224690-84-9), a 2:1 salt built on the basic nitrogen, and heavier at around 535 g/mol per unit.

Is tianeptine sodium the same as tianeptine sulfate? 

Not as solids. Once either dissolves, you're left with the same tianeptine ion, but the crystalline salts differ in molar mass, CAS number, and water behavior. The sodium is 30123-17-2 and hygroscopic; the sulfate is 1224690-84-9.

Is tianeptine sulfate stronger than tianeptine sodium? 

No. Both salts dissociate to the same tianeptine ion in solution, so neither is inherently stronger. The salt is a handling and formulation choice, not a strength one.

Which tianeptine form dissolves better in water? 

The sodium salt is readily water-soluble and takes up moisture from the air, which makes it convenient for aqueous work but demanding on storage. Published aqueous figures for the hemisulfate are thin, so confirm its solubility from your certificate of analysis before you rely on it.

What is the CAS number for tianeptine sodium and tianeptine sulfate? 

Tianeptine sodium is CAS 30123-17-2. The common tianeptine sulfate, a hemisulfate monohydrate, is CAS 1224690-84-9. Match the CAS on your certificate of analysis to the exact salt before running calculations.

Is tianeptine legal to buy for research in 2026? 

Tianeptine is not approved by the FDA for any medical use. On July 8, 2026, the DEA published a proposed rule to place tianeptine and its salts in Schedule I, and at least 15 US states already restrict or ban it. The proposal isn't final, so confirm the current status in your jurisdiction.

Is tianeptine sold for human use? 

No. Tianeptine from Nordic Chems is offered strictly for laboratory research and educational use, not for human consumption, and buyers confirm research use at checkout.