Quick Comparison

ColuracetamSunifiram
Half-Life2-3 hoursEstimated 1-2 hours (limited data)
Typical DosageStandard: 20-80 mg sublingually, 2-3 times daily. Start at 20 mg to assess sensitivity. Sublingual is strongly preferred for bioavailability.Standard: 4-8 mg sublingually. Active doses are very small — do NOT dose by weight equivalence with piracetam. Start at 4 mg. Do not use daily due to lack of long-term data. Sublingual preferred for consistent absorption.
AdministrationSublingual (strongly preferred) or oral. Oral bioavailability is limited.Sublingual (preferred) or oral. Very small doses — requires a milligram scale for accurate dosing.
Research Papers1 papers10 papers
Categories

Mechanism of Action

Coluracetam

Coluracetam's primary mechanism is enhancement of high-affinity choline uptake (HACU) in hippocampal neurons — the rate-limiting step in acetylcholine synthesis. HACU is mediated by the high-affinity choline transporter (CHT1/SLC5A7), which coluracetam upregulates or potentiates, increasing the Vmax of choline transport into presynaptic terminals. By making this process more efficient, coluracetam increases acetylcholine production and vesicular packaging via the vesicular acetylcholine transporter (VAChT) even when choline levels are normal. This enhances cholinergic transmission in the hippocampus, cortex, and retina — explaining reports of enhanced color vision and visual acuity. Coluracetam also has minor AMPA receptor positive allosteric modulation. The compound was studied for treatment-resistant depression, possibly through cholinergic modulation of mood circuits.

Sunifiram

Sunifiram (DM-235) is a positive allosteric modulator of AMPA receptors (GluA1-4 subunits) — an ampakine that slows receptor desensitization and deactivation, enhancing glutamatergic excitatory neurotransmission and calcium influx through the receptor. This calcium influx activates CaMKII (calcium/calmodulin-dependent protein kinase II), which phosphorylates GluA1 at Ser831 and is a key enzyme in long-term potentiation (LTP) and memory consolidation. Sunifiram also activates protein kinase C (PKC) isoforms, which phosphorylate GluA2 and regulate receptor trafficking. It increases acetylcholine release in the prefrontal cortex and hippocampus, likely via presynaptic nicotinic receptor activation or enhanced glutamatergic drive onto cholinergic neurons. Downstream, these mechanisms enhance CREB phosphorylation, Arc expression, and synaptic AMPA receptor insertion — the molecular basis of memory formation.

Risks & Safety

Coluracetam

Common

Headache, fatigue, brain fog at high doses.

Serious

Very limited human safety data — studied only in small trials.

Rare

Anxiety, irritability, suicidal ideation was reported in one clinical trial participant.

Sunifiram

Common

Overstimulation, headache, jaw clenching at higher doses.

Serious

No long-term human safety data. Animal studies show a wide therapeutic index.

Rare

Insomnia, anxiety, irritability.

Full Profiles