I'm not Tickbite, but, yes, tinctures would be fine, as long as he gets the proper amount.
I'm going to use this as the example - buy a good brand though, one that has a reputation of using high quality herbs.
/www.iherb.com/pr/Gaia-Herbs-Astragalus-Root-1-fl-oz-30-ml/15623?gclid=Cj0KEQjwoqvIBRD6ls6og8qB77YBEiQAcqqHe71AgmVLYCxNqOaKW78IWxQTGnSZU6ls9Dgx3e0SbMQaAmER8P8HAQSo, as you can see, if you scroll down to product overview, that the 'serving size' is one dropperful (30 drops) will give the person 667 mg/ml Herb Equivalency - so they would need to take 2 droppers full am, noon and pm (3 times a day) to get to the full dose.
BUT - they should start out on just a small amount to see how they will respond first - then slowly raise the dose up until they have reached the optimal/full dose.
Do be sure to talk to them about
detoxing too!!! It may save them a ton of pain and issues.