Buying drugs online (esp without an RX) is risky business. It is even risky to your computer to VISIT an online place like that, as they can download malware or trojans or viruses right onto your computer!

Many online suppliers sell fake drugs...they look like what you want but inside there is no drug at all, or another drug substituted. Very risky business. And after spending your money, giving them your credit card number---blech another risk--you run a high probability of having it confiscated by customs.

We do not allow illegal drug sites linked to here, for safety and legal reasons. Our guidelines include this fact.

Dr. Smith did a good job with his Spectracell comments.
There is no need to have them do testing, for the majority of people who need nutrient testing. For one thing measuring intracellular contents requires another RANGE to work with, because the nutrient tests we have now use only serum levels.

In some cases cells burst when taken in a venipuncture sample.
When this happens the red cells contents spill over into the serum and give a false (factitious) reading. This happens most commonly with potassium, but it can happen with anything.
In this case the INTRAcellular testing may be helpful. But most doctors don't have experience with it.

The testing we have today for B12 traditionally is
1) serum levels
2) MMA levels to see if B12 is being utilized by the tissues
3) transcobalamin --a new test--to measure the carrier of the B12 -- not all labs are doing this one yet.

4) and also very helpful is the DNA test for the MTHFR mutation, to see if the patient can activate folic acid and cobalamins.

Taking an oral methycobalamin today costs pennies a day. Within 3 months you can have levels up to 1000-2000 pg/ml. There isn't a single treatment, drug or nutrient, that is this available, so inexpensively, OTC and successful.

Of course if your B12 is showing normal (above 400pg/ml) you probably have something else going on to cause your PN.
You have to take the oral form on an empty stomach with no food for about an hour so it can be passively absorbed. Food will prevent this.
The dose of 1000mcg in the test that I listed to you...gave 13mcg in the serum. This is 3 to 4 times the RDA .