MK-4 (Menaquinone-4)
Also called Menatetrenone
MK-4 is the short-chain menaquinone made in the body from K1 and found in some animal foods. It has a much shorter half-life than MK-7 (about 1–2 hours), so it is typically taken in divided doses and at far higher doses (45–90 mg/day) to achieve meaningful tissue levels. MK-4 has the strongest evidence for osteoporosis in Japan (where it is prescribed as menatetrenone), but it is less commonly used as a general supplement because of the high dose and multiple daily doses required. Most people looking for a daily K2 supplement will prefer MK-7.
Best for
Bone health, high-dose protocols under clinician guidance
Absorption
High
Tolerability
Very good at standard doses
Typical timing
With a fat-containing meal, often alongside D3
How to take MK-4 (Menaquinone-4)
A typical dose of Vitamin K2: 90–180 mcg per day (MK-7) or 45–90 mg per day (MK-4). Best timing: With a fat-containing meal, often alongside D3. The form you choose mainly affects absorption and how easily it sits with your stomach, not the overall dose.