Dear Doctors,

Apologies for being back here. I do so with reluctance, but I have some concerns about Biotin and its effects on my previous vein drawn, lab tested HIV tests.

In the past I have taken Vitamin B complex supplements for general health or given to me by my GP for my carpal tunnel. I am not sure if Biotin was in these supplements, which supplements I took, and, if present, in what dosages. I also cannot remember if I took these supplements while getting my HIV tests in 2020. Concerns about Biotin seem to be a new so I am trying to understand both of your recent comments:

·      Question 7822 (1 month ago - Dr. Handsfield):

1.     “The online business about biotin interference with HIV testing is an urban myth -- and in case, applicable only to the standalone antibody tests, not the AgAb combo tests.”

·      Question 7887 (12 days ago - Dr. Handsfield):

1.     “Very large doses of biotin, with abnormally high blood levels, can interfere with the HIV AgAb (4th generation) tests.”

2.     “Having been tested for HIV with negative result at 45 days, it is 100% certain you do not have HIV, regardless of your biotin intake or diet.”

·      Question 7891 (11 days ago - Dr. Hook):

o   “To get the sort of blood levels required to affect HIV test results, the amount of biotin which is taken is typically greater than 1 mg or five times the dose of biotin found in the supplement you were taken.  Further, this potential side effect, on those rare occasions when it does occur, tends to occur in persons with recently acquired HIV.”

My questions:

·      Are the effects of biotin something to be concerned about or is this overblown and extremely rare? I feel like if serious there would be more warnings about it

·      What is considered a “very large” dose?

·      Does Biotin affect the 4^th gen tests? If so, does is it only affect the antibody component of the AbAg test and therefore has no impact of the antigen component?

·      Does biotin only affect AbAg early testing (i.e. early on during the window period) meaning that tests after the 42 day mark (like all of mine) continue to be 100% conclusive?

I am not casting doubt on what you have previously said; I want to understand if I have additional risk which requires additional testing. Logically even if I was taking biotin during both my tests in 2020 (Jan and May 2020 following a Dec 2019 exposure), any infection would have been caught by my recent April 2021 test, right?  

Thank you.

Welcome back to the Forum.  I’m sorry you continue to worry about your HIV risks.  The biotin issue has only relatively recently been described, is theoretical and has not been demonstrated to be a problem in human testing to date.  The laboratory/test tube studies which describe this potential effect clearly show that the low levels of biotin achieved with available multivitamins or B-complex supplements do not reach even close to those levels.  At present these concerns are theoretical, just as it is theoretically possible you will be struck by lightning today.  In answer to your specific questions:

·      Are the effects of biotin something to be concerned about or is this overblown and extremely rare? I feel like if serious there would be more warnings about it

The concerns regarding biotin and its effect on test results are overblown.  If it were a major problem it would have been described long ago.  A yet, I am unaware of any cases of HIV which have been missed because someone was taking biotin.  

·      What is considered a “very large” dose?

That is hard to say.  What we do know is that the levels of biotin which effect the HIV tests are far higher than attained with standard multivitamins or even vitamin B supplements. 

·      Does Biotin affect the 4^th gen tests? If so, does is it only affect the antibody component of the AbAg test and therefore has no impact of the antigen component?

The effect is on the detection system so while the laboratory/test tube studies have focused on antibody detection, I would expect that it might impact the antigen detection system as well, if it is a reall problem (which I doubt)

·      Does biotin only affect AbAg early testing (i.e. early on during the window period) meaning that tests after the 42 day mark (like all of mine) continue to be 100% conclusive?

Because the effect is related to the amount of biotin, antibodies, and antigen present, the effect if it occurs at all would be more obvious early in the course of infection and decline over time as antibody and antigen levels increased

I hope this information is helpful.  I would again urge you to believe your test results.  If you really are concerned about this, you could be sure to not take vitamins for 2-3 days over which period any excess biotin present would certainly be eliminated from the body and re-test.  Please note, I am NOT advocating this but offer it just in case your OCD on this issue continues to worry you.  EWH

Thank you, Dr. Hook. It’s reassuring to know your informed opinion is that the matter is overblown and only theoretical. A quick google does not provide much in the way of substantial answers one way or the other.

Thank you as well for confirming that biotin dosages in multivitamin and vitamin B complex tablets are well below the threshold of potentially impacting the tests. *PHEW* That really helped.

With regards to your answer to my 4^th question, if the effects of biotin are “more obvious early in the course of infection and decline over time as antibody and antigen levels increased” does that mean biotin loses its ability to impact the HIV tests as the level of antibodies and antigens rise even if consumed that day? If I understand the answers provided by Dr. Handsfield in question 7887 (see extract above), is it correct to say that a test after the 6-week mark would (as always) continue to be conclusive regardless of whether biotin was still being consumed? I am trying to reconcile the answers you and Dr. Handsfield have both provided but fear I am reaching.

May I check, apart from biotin, are there any other drugs or supplements which may have even a theoretical risk of impacting the AbAg 4^th gen test? For the longest time I thought it was a no until I chanced upon a recent forum discussion…

Lastly, your answers have allowed me to have increased confidence in my negative results from my recent checkup in April 2021. No supplements were taken then. Even IF my two tests from 2020 were impacted in any way (not saying I believe that based on your feedback), its good to lean on the most recent test. 

Thank you very much.

Thank you, Dr. Hook. FYI, the last two AgAb tests were done in May 2020 and April 2021, performed 22.5 and 11.5 weeks following potential exposure events respectively (of which yourself and Dr. Handsfield have commented). Biotin or not, this is even more reassuring.   

On a sidenote, one of the vitamin B complex supplements I may have taken contained 50 mcg of biotin, well below the 1 mg threshold you flagged as a potential risk in question #7891. There may have been other supplements, but as you said, I can’t imagine they would come close to the 1 mg dosage.

Following your most recent response, I have no additional questions. You may close this thread if you have no further comments. Thank you again for lending your expertise and for your patience. Take care and God bless.