Doctor's Best supplements: who owns the brand, which magnesium is in the bottle and how to choose

Who owns Doctor’s Best

Ken Halvorsrude and Dr James Braly founded Doctor’s Best in California in 1990. Today it’s based in Tustin, California. Its ownership history:

• from 2014 to 2016 it belonged to the private equity firm North Castle Partners;
• in 2016 the Chinese company Xiamen Kingdomway Group bought it for an undisclosed sum; the brand now operates through Kingdomway USA.

The company says its products are made and tested only at cGMP-certified sites in the US, including those of its own manufacturing arm, Vit-Best.

What Doctor’s Best is known for

The brand’s signature is branded raw materials from known suppliers, named on the product:

• Albion TRAACS – chelated magnesium;
• BioPerine – black pepper extract in its CoQ10;
• Lutemax 2020 – lutein and zeaxanthin;
• OptiMSM – MSM as a powder and in a glucosamine and chondroitin formula;
• PepZin GI – zinc carnosine; MenaQ7 – vitamin K2.

That’s useful: you know whose ingredient is in the bottle. But a branded ingredient is about the supplier, not about testing the finished product. Look for USP or NSF seals on the specific bottle.

Doctor’s Best magnesium: what’s really in the bottle

Doctor’s Best sells its magnesium mainly as High Absorption Magnesium. It’s easy to assume it’s bisglycinate, but the Supplement Facts panel says magnesium lysinate glycinate chelate (Albion). That’s magnesium bound to two amino acids, lysine and glycine.

The label in numbers:

• per the label, 2,000 mg of chelate provides 200 mg of magnesium, about 10% by weight, less than bisglycinate (about 14%);
• 200 mg is 2 tablets of 100 mg each;
• the label suggests 2 tablets twice a day, which is 400 mg of magnesium.

400 mg is above EFSA’s limit for supplemental magnesium (250 mg a day) and the US limit (350 mg). Most adults need no more than 100–200 mg from a supplement, so 1–2 tablets. See types of magnesium compared for the other forms.

Popular Doctor’s Best products and their forms

For CoQ10 forms, see our CoQ10 guide; for lutein, see eye vitamins and lutein.

Recall: Red Yeast Rice, 2014

In June 2014 Doctor’s Best recalled one lot of Red Yeast Rice, 7,379 bottles. It contained undeclared lovastatin, a prescription statin. Lovastatin can cause muscle damage and is a risk in pregnancy and liver disease. The company reported no adverse events.

Doctor’s Best strengths and weak points

With Doctor’s Best you know whose ingredient is in the bottle: the supplier is named on the label. Its magnesium is fully chelated, with no oxide added. The range is focused – magnesium, CoQ10, lutein, joints – which makes it easier to find your way around.

The drawbacks are worth knowing in advance:

• the magnesium dose suggested on the label exceeds both the European and US limits;
• the Albion chelate carries little magnesium per tablet, so you need more tablets;
• not every product has an independent seal.

Who should take care

With kidney disease, take magnesium only on medical advice. CoQ10 can weaken the effect of warfarin, so check with your GP. Glucosamine is often made from shellfish shells: if you’re allergic, check the source on the label. Red yeast rice contains a natural statin and shouldn’t be combined with statins. If you’re pregnant or breastfeeding, agree any supplement with your midwife or GP.

How to choose Doctor’s Best on iHerb

1. Decide which form you need using the nutrient guide, for example magnesium glycinate.
2. Find the Doctor’s Best product and read the “from … mg” line on the Supplement Facts panel.
3. Work out your own dose rather than following the label’s suggestion.
4. Compare the cost of a daily dose with other brands, as in our label guide.
5. Check that it ships to the UK or your EU country.