Super K with Advanced K2 Complex - 90 ct

Clinical trials typically use 100-200 mcg MK-7 daily. Life Extension Super K delivers 1500mcg K1 + 1000mcg MK-4 + 100mcg MK-7 per softgel, which we classify as Full relative to that range.

See the "Also consider" section below for two alternatives. Choose based on form preference (Softgel vs alternatives), dose adequacy, and third-party testing.

Yes — Third-Party Tested. Third-party testing verifies ingredient identity and label accuracy.

Current availability: OutOfStock. Stock status reflects the latest Amazon refresh — check the Amazon link for real-time status.

Yes, the combination of K1, MK-4, and MK-7 in Life Extension Super K is well-tolerated for daily use in healthy adults. Life Extension is a research-focused brand with over 40 years of experience. The main caution is for people on warfarin due to the high K1 content (1500mcg).

No, Life Extension Super K contains 1500mcg of vitamin K1, which directly counteracts warfarin. This is a much higher K1 dose than most K2-only supplements. If you take warfarin, consult your doctor before taking any vitamin K supplement, but this product is particularly problematic.

The 1500mcg K1 dose is safe for healthy adults not on anticoagulants. K1 is the primary clotting form of vitamin K and is found naturally in leafy greens. This amount is roughly equivalent to eating a large serving of kale or spinach. It supports healthy blood coagulation.

Side effects are rare at the doses provided. Some people report mild digestive discomfort when starting. The oil-based softgel is generally gentle on the stomach. With over 1,500 positive Amazon reviews at 4.6 stars, consumer satisfaction with tolerability is high.

Yes, this is an excellent combination. Life Extension Super K provides comprehensive vitamin K coverage that directs supplemental calcium to bones rather than arteries. The K2 forms (MK-4 and MK-7) are particularly important for calcium metabolism when taking D3 and calcium.

The recommended dose is one softgel daily, providing 1500mcg K1, 1000mcg MK-4, and 100mcg MK-7. Take with a fat-containing meal for optimal absorption. The bottle contains 90 softgels for a three-month supply.