Going a bit more complex but not very much so, Wesson can be mixed with ethyl oleate USP in for example a 50/50 mixture. The reason to do this is to produce a more easily-flowing final product. If doing so, the simplest thing is to make a pre-mix beforehand, such as 100 mL each of Wesson and of the ethyl oleate.
Below, we’ll call the carrier oil “the carrier,” whether it’s pure Wesson or the above mixture with ethyl oleate, or some other oil or mixture of your choice.
Second, let’s consider the materials other than your anabolic steroids that might be added to the carrier oil. These would generally be benzyl benzoate USP, to add solubilizing power, and/or benzyl alcohol USP to act as a bacteriostatic. For simplicity, you could mix 20 parts benzyl benzoate to 1 part benzyl alcohol to create a single additive solution. An example way of doing this would be to mix together 100 mL benzyl benzoate and 5 mL benzyl alcohol.
Example preparations of 100 mL total for personal use would then be:
Optionally, oil can be added as needed to obtain a measured desired volume. For example, a vial might have been filled with exactly 100 mL of a convenient sterile substance such as benzyl benzoate, marked with tape to indicate that level, and then drained. On making the preparation, a little less than the above carrier would be used; the product would be “topped off” to the marked volume at the end. Another way is to do the preparation inside a syringe with a sterile filter already in place. Ordinarily a smaller volume such as only 30 mL would be prepared at a time when using that method.
However, the above mL values for carrier will be close enough for all practical purposes – a difference of for example 1% in steroid concentration is not important at all.
Some might say that the above benzyl alcohol concentration is too low, but it’s now common or possibly universal practice in European injectables for BA to be just under 1% concentration. The material is a known irritant and allergic sensitizer. With careful practices it can even be omitted – personally I always do so myself – but many like to have it present. If bacteria are allowed into the vial, BA will not reverse that contamination in any case, whether at 1% or 5%. The key really is proper practices, not BA.