veterinary B complex/B12 question

I was considering buying some veterinary B12 off Amazon. Would you guys feel Ok with shooting the stuff? I see some B complex "mixes", as well as just B12. Both products come in different concentrations (mcg/Ml). How many mcgs should someone be injecting? If you would feel safe using either, which one would you use...complex propriety blend, or just B12?

Here's a list of the ingredients in one of the B complex products:

Fortified, concentrated B Complex injectable contains all six B Vitamins. Contains 100mcg of B12/ml. Each mL of sterile aqueous solution contains: Thiamine Hydrochloride (B1) - 100 mg Riboflavin (B2) (as Riboflavin 5'-Phosphate Sodium) - 5 mg Niacinamide - 100 mg Pyridoxine Hydrochloride (B6) - 10 mg d-Panthenol - 10 mg Cyanocobalamin (B12) - 100 mcg With Citric Acid and Benzyl Alcohol 1.5% v/v (preservative).

Well would you rather use vet grade or human pharma grade??? Hmm! Lol!
Well, before I started TRT and before I was offered a script for B12 (methyl) I used the following veterinarian grade from a Tractor Supply in my home town:
AGRI LABORATORIES LTD.
FORTIFIED VITAMIN B COMPLEX
AgriLabs Injection
For Animal Use Only
Keep Out of Reach of Children
COMPOSITON: Each mL of sterile aqueous solution contains:
Thiamine Hydrochloride (B1) 100 mg
Riboflavin (B2) (as Riboflavin 5'-Phosphate Sodium) 5 mg
Niacinamide 100 mg
Pyridoxine Hydrochloride (B6) 10 mg
d-Panthenol 10 mg
Cyanocobalamin (B12) 100 mcg
With Citric Acid and Benzyl Alcohol 1.5% v/v (preservative).

When the doctor received my first round of blood work she was shocked at how great my B vitamins were!
So, is it safe----ah yea! Is it as good as pharma grade? I don't believe so. BUT, IT WILL GET THE JOB DONE UNTIL YOU GET A SCRIPT!