The answer would be, “It depends”
To understand this we need to understand how both medical systems work on the fundamental level.
Allopathy works on a material plane through material doses of drug substances, acting on mainly the symptoms you can see through the naked eye or in lab diagnosis. Here, they treat all the patients alike based on the symptoms present.
Homoeopathy is more on the line of PHARMACOGENOMICS working on a dynamic plane targeting your phenotype where both the role of your genotype and epigenetics comes into play. Here the medicines are delivered through dynamic doses of drug substances. So, the medicines are given not merely on lab diagnosis but instead by considering your phenotype along with the lab diagnosis. Here, not all the patients presenting with the same symptoms are treated alike but instead are treated after considering their phenotype.
Let’s take an example to understand this further by considering a tendency to be allergic. Now, Allopathy will control an allergic reaction by giving you a drug substance eg. Cetirizine which will block the action of histamine ie. a substance responsible for allergic reaction. So, here Cetirizine undoubtedly remains the go-to drug for cases of allergies. And, no doubt controls the situation temporarily as well.
But, “Why are you allergic in the first place?” or “Will these allergic reactions stop if you keep on having ‘Cetirizine’?” Now, the role of Homoeopathy comes in, which will provide you with the medicine by matching “Your Phenotype” with a “Medicine Phenotype” curing you in a way so that you do not get such allergic reactions. Here, there will not be any go-to medicine that you take for most cases of allergies. Homoeopathic medicine given in cases will depend from person to person based on their phenotype.
Now, coming back to the question, Is it safe to take both Homoeopathy and Allopathy together? As I mentioned in the first place, it depends.
YES, It is safe because both of them as explained above are acting on two different planes ie. one is acting on a Dynamic plane and the other is acting on the material plane. So, the mode of action will not interfere majorly. Also, many times, on the path to recovery, you will require to control the external symptoms or a priority before curing the tendency. In these cases, Allopathic doses are slowly tapered down till the time you no longer need them. Eg. in cases of severe allergic reaction or even elevated blood sugar levels etc. Here, a Homoeopathic doctor will give your medicine according to your phenotype to cure your root cause and meanwhile reducing the doses of allopathic medicines slowly. So, in this case, ‘Yes’, it is safe to take both together if you look at the treatment as a whole.
Now coming onto when it is NOT advisable to take it simultaneously. Because it would impact the course of treatment in case you are taking Homoeopathy for chronic conditions in a negative way. Constantly fiddling with the immune system by suppressing the external symptoms, may it be a fever, allergy or anything, will not let your condition heal. In addition, there are several medicines where you can experience the adverse effects of having them simultaneously with a drug to which they may be reactive as well.
So, to summarize, you need to consult your doctor before taking both together. Because if you want to heal, then you need to trust your doctor with the same. Because, here, only your doctor can take a call. Patients who self-prescribe, will not be able to take the right decision and will end up delaying their treatment or suffering adverse reactions.