<PAGE>
SUPPLEMENT DATED OCTOBER 26, 1998, TO
THE PROSPECTUS DATED MAY 1, 1998
STRATEGIC ADVANTAGE VARIABLE UNIVERSAL LIFE
A FLEXIBLE PREMIUM VARIABLE LIFE INSURANCE POLICY
ISSUED BY
SECURITY LIFE OF DENVER INSURANCE COMPANY
AND
SECURITY LIFE SEPARATE ACCOUNT L1
THIS SUPPLEMENT UPDATES CERTAIN INFORMATION CONTAINED IN YOUR PROSPECTUS.
PLEASE READ IT CAREFULLY AND KEEP IT WITH YOUR PROSPECTUS FOR FUTURE REFERENCE.
The first sentence in the "Policy Loans" section on page 28 is changed to read:
"At any time after the first policy Monthly Processing Date, or as
otherwise required by law, the Owner may borrow against the Policy by using
it as security for a loan."
Effective July 6, 1998, INVESCO Funds Group, Inc. ("IFG"), the investment
adviser to INVESCO Variable Investment Funds, Inc., changed the arrangements by
which it voluntarily absorbs certain expenses of the INVESCO VIF - Total Return
Portfolio, INVESCO VIF - Industrial Income Portfolio, INVESCO VIF - High Yield
Portfolio, INVESCO VIF - Utilities Portfolio and INVESCO VIF - Small Company
Growth Fund. See Pages 35 - 36 of the prospectus. The annual expenses of these
Portfolios, restated to reflect these changes, are as follows:
<TABLE>
<CAPTION>
PORTFOLIO INVESTMENT OTHER EXPENSES TOTAL
MANAGEMENT PORTFOLIO
FEE EXPENSES
===================================================================
<S> <C> <C> <C>
INVESCO VIF - Total 0.75% 0.40% 1.15%
Return Portfolio
INVESCO VIF - Industrial 0.75% 0.40% 1.05%
Income Portfolio
INVESCO VIF - High 0.60% 0.45% 1.05%
Yield Portfolio
INVESCO VIF - 0.60% 0.55% 1.15%
Utilities Portfolio
INVESCO VIF - Small 0.75% 0.50% 1.25%
Company Growth
Fund
</TABLE>
* * *
The illustrations of death benefits, account values and surrender values, and
accumulated premiums included on pages 46 - 53 of the prospectus reflect, among
other policy fees, charges, and costs, the simple average of total Portfolio
expenses for all Portfolios available through the Policy. Taking into account
the changes affecting the INVESCO VIF Portfolios described above, this simple
average increases from .7909% to .8387%.
