Lithium ascorbate and lithium carbonate are both lithium salts, but they are very different. Learn about their safety and efficiency.

Formula Differences

Lithium salts can be divided into organic and inorganic forms. Lithium carbonate is inorganic. It is easy and inexpensive to produce, so it is widely used in psychiatry. 

The body does not fully absorb lithium carbonate to other lithium forms. The more lithium carbonate is present in the body, the more lithium the kidneys must process and excrete through urine.

In summary, for lithium carbonate compared to organic salts:

• Absorption is slower.

• Higher doses are required.

• Excess lithium must be cleared through the kidneys.

Because of this, inorganic lithium salts may cause more side effects compared to organic lithium salts such as lithium ascorbate.

Dosage

Lithium carbonate is a prescription medication used under medical supervision, typically at daily doses ranging from 56.4 mg to 338.4 mg of elemental lithium or higher depending on the condition being treated.

Lithium ascorbate supplements are generally used at much lower doses, such as 1 or 5 mg of elemental lithium per serving.

Animal studies suggest that lithium ascorbate may have a more favorable safety profile than lithium carbonate. In animal studies, researchers evaluated LD50 - the lethal dose for 50% of test animals. The higher the LD50, the lower the acute toxicity. For lithium ascorbate, LD50 was estimated as 6,334 mg/kg, and for lithium carbonate it was estimated as 531 mg/kg. 

Effects

Across these six preclinical animal studies, lithium ascorbate generally produced broader and stronger behavioral, stress-protective, anticonvulsant, and neuroprotective effects than lithium carbonate at the doses tested. 

1. Primary generalized seizure model

Lithium ascorbate reduced more seizure measures and better preserved neurons and myelin, while lithium carbonate mainly shortened seizure duration and showed little histological neuroprotection.

2. Comparative forced-swim study

At approximately equal elemental-lithium doses, lithium ascorbate reduced depressive-like behavior by 35%, whereas lithium carbonate produced almost no effect.

3. Elevated-plus-maze and forced-swim study

Lithium ascorbate showed dose-dependent anxiolytic and antidepressant-like effects and remained active after withdrawal, while lithium carbonate was generally similar to placebo.

4. Open-field test

Lithium ascorbate increased locomotor and exploratory behavior and reduced stress-related signs, whereas lithium carbonate did not significantly differ from stressed controls.

5. Tail-suspension and simulated transport-stress study

Lithium ascorbate reduced immobility, adrenaline, and norepinephrine and improved eosinophil responses, while lithium carbonate showed no comparable behavioral or biochemical effects.

6. Porsolt forced-swim and withdrawal study

Lithium ascorbate produced a much larger and longer-lasting antidepressant-like effect, while lithium carbonate showed only a small delayed effect.

Because these lithium salts differ in formulation, dosage, intended use, and regulatory status, lithium ascorbate supplements should not be considered equivalent to prescription lithium carbonate. They are designed for different purposes and should not be substituted for one another. 

Author

Science Writer Vlada Sukhanovskaya

Read Next

• A Psychiatrist’s View On Lithium Ascorbate

• Lithium Ascorbate: A New Look at an Old Element

• Preclinical Studies of Lithium Ascorbate: Proven Safety

Scientific Sources

• Torshin, I. Y., Gromova, O. A., Ostrenko, K. S., Filimonova, M. V., Gogoleva, I. V., Demidov, V. I., & Kalacheva, A. G. (2022). Lithium Ascorbate as a Promising Neuroprotector: Fundamental and Experimental Studies of an Organic Lithium Salt. Molecules (Basel, Switzerland), 27(7), 2253 https://www.mdpi.com/1420-3049/27/7/2253

• A complex study of the pharmacokinetics and compartmentalization of lithium ascorbate in 11 biosubstrates https://cdn.shopify.com/s/files/1/0632/4568/0810/files/Compartmentalization.pdf?v=1772616336

• Study of the Effects of Organic and Inorganic Lithium Salts on a Model of Primary Generalized Seizures in Rats
  V. I. Demidov, A. G. Kalacheva, T. E. Bogacheva, I. Yu. Torshin, O. A. Gromova, and V. V. Rastashansky https://cdn.shopify.com/s/files/1/0632/4568/0810/files/a_model_of_primary_generalized_seizures_in_rats.pdf?v=1782303157
• Study of the Antidepressant and Anxiolytic Effects of Various Lithium Salts, Konstantin Ostrenko and Vyacheslav Rastashansky https://cdn.shopify.com/s/files/1/0632/4568/0810/files/Study_of_the_Antidepressant_and_Anxiolytic_Effects_of_Various_Lithium_Salts.pdf?v=1782295342
• Comparison of the Antidepressant and Anxiolytic Effects of Lithium Ascorbate and Lithium Carbonate with a Positive Control, V. A. Galochkin and K. S. Ostrenko https://cdn.shopify.com/s/files/1/0632/4568/0810/files/antidepressant_and_anxiolytic_effects_of_lithium_ascorbate_and_lithium_carbonate_with_a_positive_control.pdf?v=1782294685
• Comparative Analysis of the Stress-Protective Effects of Lithium Salts in the Open Field Test, A. A. Deltsov and S. V. Pozyabin https://cdn.shopify.com/s/files/1/0632/4568/0810/files/Open_field_test.pdf?v=1775470107
• Studies of the Antidepressant and Anxiolytic Effects of Lithium Salts and Mixtures in Wistar Mice Using the Tail Suspension Test and Simulated Transport Stress, K. S. Ostrenko https://cdn.shopify.com/s/files/1/0632/4568/0810/files/Simulated_transport_stress.pdf?v=1775470107
• Study of the Antidepressant and Anxiolytic Effects of Lithium Salts and Mixtures in Wistar Rats Using the Porsolt Forced Swimming Test, K. S. Ostrenko https://cdn.shopify.com/s/files/1/0632/4568/0810/files/Swimming_test.pdf?v=1775470107

FAQs

1. What is the main difference between lithium ascorbate and lithium carbonate?

Lithium carbonate is an inorganic lithium salt used as a prescription medication in psychiatry. Lithium ascorbate is an organic lithium salt used in much smaller amounts in supplements. They differ in chemical structure, dosage, intended use, and regulatory status.

2. Are lithium ascorbate and lithium carbonate used at the same dose?

No. Prescription lithium carbonate is generally used at substantially higher elemental-lithium doses and requires medical supervision. Lithium ascorbate supplements typically provide much smaller amounts, such as 1 or 5 mg of elemental lithium per serving.

3. Which lithium salt appeared more effective in the animal studies?

Across the six preclinical studies described in the article, lithium ascorbate generally produced stronger behavioral, stress-protective, anticonvulsant, and neuroprotective effects at the tested doses. Lithium carbonate often produced smaller effects or did not differ significantly from the control groups.

4. What did the simulated transport-stress study find?

In mice exposed to simulated transport stress, lithium ascorbate reduced adrenaline and norepinephrine levels and improved eosinophil responses. Lithium carbonate did not produce comparable changes in these stress-related markers.

5. Can lithium ascorbate replace prescription lithium carbonate?

No. Lithium ascorbate supplements and prescription lithium carbonate are not interchangeable. Prescription lithium should not be stopped, replaced, or adjusted without guidance from a qualified healthcare professional.

Summary Of The Article

Lithium ascorbate and lithium carbonate differ in chemistry, dosage, use, and safety. Lithium carbonate is a prescription psychiatric drug, while lithium ascorbate is used in lower-dose supplements. Six animal studies found stronger effects and lower acute toxicity for lithium ascorbate, but these findings have not been confirmed in humans, and the salts are not interchangeable.