Potency is no fancy. One cannot imagine it and prescribe it when a remedy is selected. Potency decision is neither creative tool nor fixed parameter in the prescribing method. It is decided upon the experience and knowledge of medicines. It is a point of great concern as to what is correct potency although none of the high or low potency is going to kill the patient. The cure does not only depend upon the use of low or high potencies. Selection of right remedy in tune with totality of symptoms is essential. It is very interesting to note that sometimes, repeated doses of low potencies have to be given and in many cases low potencies have brought in better results than high potencies. Let us take the case of toothache. Low potencies used in frequent doses have fetched positive results but the cure is most temporary since succession of such change is affected. In the case of high potencies no effective changes are noted unless the remedies are strictly homoeopathic. High potencies travel deeper into the body and act longer. They stir up the constitution and mental picture of the patient. Use of rare doses of mother tinctures for a longer period show better results than the massive doses with indiscriminate repetitions. Medicines like chelidonium, ceanothus, and Beriberi vulg., are abused by us in too frequent doses. Much better results can be achieved from these by the 3^rd or 6^th potencies.

High or low potency, the rule of repetition has to be observed. A dose is not to be repeated till the effect of the dose given earlier ceases its action. Repetition does not mean that a single dose of Bryonia will cure cough altogether or a dose of aconite is sufficient to cure pyrexia. In acute cases, the repletion is needed and even there may be change in potency depending upon the cases.

Here I give some hints from masters of homoepathy for your knowledge:

• If the selection of remedy is correct, whether you give 6, 30 or 200, it has to work.
• In case of acute disorders like toothache, tonsillitis, stomatitis, colics, give 30^th potency in frequent doses since these are only physical disorders.
• In case the patient has already consulted other systems of medicines and come to homoeopathy with above problems, give 200^th potency once.
• If 30^th is giving partial results, try 200^th now in infrequent doses.
• In case of above acute disorders, if the recurrences take place, use 200^th without repetition.
• For exclusive mental problems, use 1000^th initially and go higher later depending upon the condition.
• In case antidote was given and again you find the same symptoms ( in between the original remedy given and the antidote), revert to same potency that you gave in the start.
• Potency selection has a relation with the built of the patient. The strength and stability of the patient to withstand the high potency needs consideration. In weak and old persons, the first trial should be low potency.
• The polychrests should be given in 200^th potencywhen the disease os of acute condition. In children between the age of 2 to 10, start with 200 th. Medicines like Nux, Bryonia, Belladona, Ignatia, Aconite act better in 200^th but medicines like acid phos., lachesis, stannum, plumbum, zinc met., (mostly metals) should not be given higher than 200 th.
• Nosodes should be given in 200^th in single dose.
• Giving high potency without trying low potency will be suppression in most of cases.
• Rising from 30^th to 1 M in progression depending upon the improvement is right way.
• Until and unless, there is surety about true selection, do not give Graphite or Lachesis in 200^th in skin diseases. It may aggravate.
• Do not give Kali Bich in less than 30^th because abundant experience has convinced that it does better than the low trituration (Nash)
• Lycopodium higher than 12 c in severe duodenal ulcer pains may precipitate a perforation (H.W. Boyd)
• Mercurius cyanatus below 6c may aggravate the case (Boericke)
• Natrum Mur lower than 30^th in malaria cases should not be given (Anshutz)
• In hydrogenoid patients who have nephritis, not higher than a dilution of 6x be used in Natrum Mur. (E. Wright)
• In nose bleeding vomiting and purging, do not use Natrum sulph 200. (E. Wright)
• Nitric acid should not be used in the form of trituration or dispensed with on pellets as it will decompose on sugar with the formation of oxalic acid, Use it in 30^th potency. (Pierce)
• In advance cases of phthisis, phosphorus should not be used in higher potency. 30^th or 200^th is enough. (Bhanja)
• Phosphorus very low will act as a poison. ( Kent)
• Psorinum should not be used higher than 30^th in cases of asthma.(E. Wright)
• Sulpher in any potency above 30^th should be given with some caustion where there is any doubt. It is well to test the case with lower potencies, 3, 6 or 12 or the tincture and only give higher potencies as the success of the lower warrants.(Charles E. Wheeler)
• Sulpher should not be given in too high potency in chronic skin affections at the start. This would aggravate and spoil the case.
• To give very high potency of any medicine to a feeble and extremely sensitive, old complaints and symptoms come back too violently and too hurriedly and fail to sustain the curative action long enough to eradicate the underlying miasm. ( Kent)
• Apis mel should not be given in low potency and in frequent doses to pregnant women as it may bring about a miscarriage, especially before or at the third month.(Farrington)
• In neuralgia, Arsenic should not be given in too low potency since it is likely to bring aggravation.
• Belladona should not be given in low potency in case of pains of glaucoma. Watch it closely if you give in 30^th or 200 th. (Royal)
• Caulophylium should not be given lower than 200 th. Like Secale it be trifled with or of no importance (Allen)
• Collinsonia is harmful in low potencies in organic heart diseases.
• Cyclamen may disturb eye sight if given in low potency.
• Do not use Heloderma stronger than 30 th.
• In ear pains, do not use Ferrum Phos below 12x potency. The low will only work when high fails. (T.K. Moore)
• Drosera in 30^th potency, a single dose, is sufficient for the cure of epidemic whooping cough. Care should be taken not to give a second dose. (Hahnemann)

It would be very easy for you to use any potency of the remedy you have selected provided you are sure that the selection is correct. This is the secret of potency decision.